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42 >Privoxy 3.0.27 User Manual</TH
83 >14.1. Regular Expressions</A
89 > uses Perl-style <SPAN
94 HREF="actions-file.html"
98 HREF="filter-file.html"
102 HREF="http://www.pcre.org/"
111 > If you are reading this, you probably don't understand what <SPAN
115 > are, or what they can do. So this will be a very brief
116 introduction only. A full explanation would require a <A
117 HREF="http://www.oreilly.com/catalog/regex/"
122 > Regular expressions provide a language to describe patterns that can be
123 run against strings of characters (letter, numbers, etc), to see if they
124 match the string or not. The patterns are themselves (sometimes complex)
125 strings of literal characters, combined with wild-cards, and other special
126 characters, called meta-characters. The <SPAN
128 >"meta-characters"</SPAN
130 special meanings and are used to build complex patterns to be matched against.
131 Perl Compatible Regular Expressions are an especially convenient
135 > of the regular expression language.</P
137 > To make a simple analogy, we do something similar when we use wild-card
138 characters when listing files with the <B
145 > matches all filenames. The <SPAN
149 character here is the asterisk which matches any and all characters. We can be
150 more specific and use <TT
153 > to match just individual
156 >"dir file?.text"</SPAN
164 >, etc. We are pattern
165 matching, using a similar technique to <SPAN
167 >"regular expressions"</SPAN
170 > Regular expressions do essentially the same thing, but are much, much more
171 powerful. There are many more <SPAN
173 >"special characters"</SPAN
175 building complex patterns however. Let's look at a few of the common ones,
176 and then some examples:</P
190 > - Matches any single character, e.g. <SPAN
226 > - The preceding character or expression is matched ZERO or ONE
247 > - The preceding character or expression is matched ONE or MORE
268 > - The preceding character or expression is matched ZERO or MORE
292 > character denotes that
293 the following character should be taken literally. This is used where one of the
294 special characters (e.g. <SPAN
297 >) needs to be taken literally and
298 not as a special meta-character. Example: <SPAN
300 >"example\.com"</SPAN
302 sure the period is recognized only as a period (and not expanded to its
303 meta-character meaning of any single character).
323 > - Characters enclosed in brackets will be matched if
324 any of the enclosed characters are encountered. For instance, <SPAN
328 matches any numeric digit (zero through nine). As an example, we can combine
332 > to match any digit one of more times: <SPAN
355 > - parentheses are used to group a sub-expression,
356 or multiple sub-expressions.
379 > character works like an
383 > conditional statement. A match is successful if the
384 sub-expression on either side of <SPAN
387 > matches. As an example:
390 >"/(this|that) example/"</SPAN
391 > uses grouping and the bar character
392 and would match either <SPAN
394 >"this example"</SPAN
407 > These are just some of the ones you are likely to use when matching URLs with
411 >, and is a long way from a definitive
412 list. This is enough to get us started with a few simple examples which may
413 be more illuminating:</P
425 that uses the common combination of <SPAN
432 denote any character, zero or more times. In other words, any string at all.
433 So we start with a literal forward slash, then our regular expression pattern
437 >) another literal forward slash, the string
441 >, another forward slash, and lastly another
446 a directory path here. This will match any file with the path that has a
447 directory named <SPAN
454 any characters, and this could conceivably be more forward slashes, so it
455 might expand into a much longer looking path. For example, this could match:
458 >"/eye/hate/spammers/banners/annoy_me_please.gif"</SPAN
462 >"/banners/annoying.html"</SPAN
463 >, or almost an infinite number of other
464 possible combinations, just so it has <SPAN
470 > And now something a little more complex:</P
478 >/.*/adv((er)?ts?|ertis(ing|ements?))?/</TT
482 We have several literal forward slashes again (<SPAN
486 building another expression that is a file path statement. We have another
490 >, so we are matching against any conceivable sub-path, just so
491 it matches our expression. The only true literal that <SPAN
498 > our pattern is <SPAN
502 the forward slashes. What comes after the <SPAN
511 > means the preceding expression (either a
512 literal character or anything grouped with <SPAN
516 can exist or not, since this means either zero or one match. So
519 >"((er)?ts?|ertis(ing|ements?))"</SPAN
520 > is optional, as are the
521 individual sub-expressions: <SPAN
527 >"(ing|ements?)"</SPAN
538 >. We have two of those. For instance,
541 >"(ing|ements?)"</SPAN
542 >, can expand to match either <SPAN
555 >. What is being done here, is an
556 attempt at matching as many variations of <SPAN
558 >"advertisement"</SPAN
560 similar, as possible. So this would expand to match just <SPAN
576 >"advertisement"</SPAN
580 >"advertisements"</SPAN
581 >. You get the idea. But it would not match
584 >"advertizements"</SPAN
588 >). We could fix that by
589 changing our regular expression to:
592 >"/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/"</SPAN
593 >, which would then match
602 >/.*/advert[0-9]+\.(gif|jpe?g)</TT
606 another path statement with forward slashes. Anything in the square brackets
610 > can be matched. This is using <SPAN
614 shorthand expression to mean any digit one through nine. It is the same as
618 >. So any digit matches. The <SPAN
622 means one or more of the preceding expression must be included. The preceding
623 expression here is what is in the square brackets -- in this case, any digit
624 one through nine. Then, at the end, we have a grouping: <SPAN
628 This includes a <SPAN
631 >, so this needs to match the expression on
632 either side of that bar character also. A simple <SPAN
635 > on one side, and the other
636 side will in turn match either <SPAN
646 > means the letter <SPAN
650 can be matched once or not at all. So we are building an expression here to
651 match image GIF or JPEG type image file. It must include the literal
655 >, then one or more digits, and a <SPAN
659 (which is now a literal, and not a special character, since it is escaped
663 >), and lastly either <SPAN
673 >. Some possible matches would
676 >"//advert1.jpg"</SPAN
680 >"/nasty/ads/advert1234.gif"</SPAN
684 >"/banners/from/hell/advert99.jpg"</SPAN
685 >. It would not match
689 > (no leading slash), or
692 >"/adverts232.jpg"</SPAN
693 > (the expression does not include an
699 >"/advert1.jsp"</SPAN
704 in the expression anywhere).</P
706 > We are barely scratching the surface of regular expressions here so that you
707 can understand the default <SPAN
711 configuration files, and maybe use this knowledge to customize your own
712 installation. There is much, much more that can be done with regular
713 expressions. Now that you know enough to get started, you can learn more on
716 > More reading on Perl Compatible Regular expressions:
718 HREF="http://perldoc.perl.org/perlre.html"
720 >http://perldoc.perl.org/perlre.html</A
723 > For information on regular expression based substitutions and their applications
724 in filters, please see the <A
725 HREF="filter-file.html"
726 >filter file tutorial</A
735 NAME="INTERNAL-PAGES"
736 >14.2. Privoxy's Internal Pages</A
742 > proxies each requested
743 web page, it is easy for <SPAN
747 trap certain special URLs. In this way, we can talk directly to
752 configured, see how our rules are being applied, change these
753 rules and other configuration options, and even turn
757 > filtering off, all with
760 > The URLs listed below are the special ones that allow direct access
768 > must be running to access these. If
769 not, you will get a friendly error message. Internet access is not
785 HREF="http://config.privoxy.org/"
787 >http://config.privoxy.org/</A
792 > There is a shortcut: <A
797 doesn't provide a fall-back to a real page, in case the request is not
806 > Show information about the current configuration, including viewing and
807 editing of actions files:
816 HREF="http://config.privoxy.org/show-status"
818 >http://config.privoxy.org/show-status</A
825 > Show the source code version numbers:
834 HREF="http://config.privoxy.org/show-version"
836 >http://config.privoxy.org/show-version</A
843 > Show the browser's request headers:
852 HREF="http://config.privoxy.org/show-request"
854 >http://config.privoxy.org/show-request</A
861 > Show which actions apply to a URL and why:
870 HREF="http://config.privoxy.org/show-url-info"
872 >http://config.privoxy.org/show-url-info</A
879 > Toggle Privoxy on or off. This feature can be turned off/on in the main
883 > file. When toggled <SPAN
890 continues to run, but only as a pass-through proxy, with no actions taking
900 HREF="http://config.privoxy.org/toggle"
902 >http://config.privoxy.org/toggle</A
907 > Short cuts. Turn off, then on:
916 HREF="http://config.privoxy.org/toggle?set=disable"
918 >http://config.privoxy.org/toggle?set=disable</A
929 HREF="http://config.privoxy.org/toggle?set=enable"
931 >http://config.privoxy.org/toggle?set=enable</A
944 >14.3. Chain of Events</A
947 > Let's take a quick look at how some of <SPAN
951 core features are triggered, and the ensuing sequence of events when a web
952 page is requested by your browser:</P
958 > First, your web browser requests a web page. The browser knows to send
962 >, which will in turn,
963 relay the request to the remote web server after passing the following
972 > traps any request for its own internal CGI
977 >) and sends the CGI page back to the browser.
985 > checks to see if the URL
987 HREF="actions-file.html#BLOCK"
993 so, the URL is then blocked, and the remote web server will not be contacted.
995 HREF="actions-file.html#HANDLE-AS-IMAGE"
998 >"+handle-as-image"</SPAN
1003 HREF="actions-file.html#HANDLE-AS-EMPTY-DOCUMENT"
1006 >"+handle-as-empty-document"</SPAN
1009 are then checked, and if there is no match, an
1013 > page is sent back to the browser. Otherwise, if
1014 it does match, an image is returned for the former, and an empty text
1015 document for the latter. The type of image would depend on the setting of
1017 HREF="actions-file.html#SET-IMAGE-BLOCKER"
1020 >"+set-image-blocker"</SPAN
1023 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
1028 > Untrusted URLs are blocked. If URLs are being added to the
1032 > file, then that is done.
1037 > If the URL pattern matches the <A
1038 HREF="actions-file.html#FAST-REDIRECTS"
1041 >"+fast-redirects"</SPAN
1044 it is then processed. Unwanted parts of the requested URL are stripped.
1049 > Now the rest of the client browser's request headers are processed. If any
1050 of these match any of the relevant actions (e.g. <A
1051 HREF="actions-file.html#HIDE-USER-AGENT"
1054 >"+hide-user-agent"</SPAN
1057 etc.), headers are suppressed or forged as determined by these actions and
1063 > Now the web server starts sending its response back (i.e. typically a web
1069 > First, the server headers are read and processed to determine, among other
1070 things, the MIME type (document type) and encoding. The headers are then
1071 filtered as determined by the
1073 HREF="actions-file.html#CRUNCH-INCOMING-COOKIES"
1076 >"+crunch-incoming-cookies"</SPAN
1080 HREF="actions-file.html#SESSION-COOKIES-ONLY"
1083 >"+session-cookies-only"</SPAN
1087 HREF="actions-file.html#DOWNGRADE-HTTP-VERSION"
1090 >"+downgrade-http-version"</SPAN
1099 HREF="actions-file.html#FILTER"
1106 HREF="actions-file.html#DEANIMATE-GIFS"
1109 >"+deanimate-gifs"</SPAN
1112 action applies (and the document type fits the action), the rest of the page is
1113 read into memory (up to a configurable limit). Then the filter rules (from
1117 > and any other filter files) are
1118 processed against the buffered content. Filters are applied in the order
1119 they are specified in one of the filter files. Animated GIFs, if present,
1120 are reduced to either the first or last frame, depending on the action
1121 setting.The entire page, which is now filtered, is then sent by
1125 > back to your browser.
1129 HREF="actions-file.html#FILTER"
1136 HREF="actions-file.html#DEANIMATE-GIFS"
1139 >"+deanimate-gifs"</SPAN
1145 > passes the raw data through
1146 to the client browser as it becomes available.
1151 > As the browser receives the now (possibly filtered) page content, it
1152 reads and then requests any URLs that may be embedded within the page
1153 source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
1154 frames), sounds, etc. For each of these objects, the browser issues a
1155 separate request (this is easily viewable in <SPAN
1159 logs). And each such request is in turn processed just as above. Note that a
1160 complex web page will have many, many such embedded URLs. If these
1161 secondary requests are to a different server, then quite possibly a very
1162 differing set of actions is triggered.
1167 > NOTE: This is somewhat of a simplistic overview of what happens with each URL
1168 request. For the sake of brevity and simplicity, we have focused on
1172 > core features only.</P
1180 >14.4. Troubleshooting: Anatomy of an Action</A
1188 HREF="actions-file.html#ACTIONS"
1191 HREF="actions-file.html#FILTER"
1194 to any given URL can be complex, and not always so
1195 easy to understand what is happening. And sometimes we need to be able to
1206 doing. Especially, if something <SPAN
1210 is causing us a problem inadvertently. It can be a little daunting to look at
1211 the actions and filters files themselves, since they tend to be filled with
1213 HREF="appendix.html#REGEX"
1214 >regular expressions</A
1215 > whose consequences are not
1216 always so obvious.</P
1218 > One quick test to see if <SPAN
1221 > is causing a problem
1222 or not, is to disable it temporarily. This should be the first troubleshooting
1223 step (be sure to flush caches afterward!). Looking at the
1224 logs is a good idea too. (Note that both the toggle feature and logging are
1228 > file settings, and may need to be
1234 > Another easy troubleshooting step to try is if you have done any
1235 customization of your installation, revert back to the installed
1236 defaults and see if that helps. There are times the developers get complaints
1237 about one thing or another, and the problem is more related to a customized
1238 configuration issue.</P
1245 HREF="http://config.privoxy.org/show-url-info"
1247 >http://config.privoxy.org/show-url-info</A
1249 page that can show us very specifically how <SPAN
1253 are being applied to any given URL. This is a big help for troubleshooting.</P
1255 > First, enter one URL (or partial URL) at the prompt, and then
1260 how the current configuration will handle it. This will not
1261 help with filtering effects (i.e. the <A
1262 HREF="actions-file.html#FILTER"
1268 one of the filter files since this is handled very
1269 differently and not so easy to trap! It also will not tell you about any other
1270 URLs that may be embedded within the URL you are testing. For instance, images
1271 such as ads are expressed as URLs within the raw page source of HTML pages. So
1272 you will only get info for the actual URL that is pasted into the prompt area
1273 -- not any sub-URLs. If you want to know about embedded URLs like ads, you
1274 will have to dig those out of the HTML source. Use your browser's <SPAN
1278 > option for this. Or right click on the ad, and grab the
1281 > Let's try an example, <A
1282 HREF="http://google.com"
1286 and look at it one section at a time in a sample configuration (your real
1287 configuration may vary):</P
1296 > Matches for http://www.google.com:
1298 In file: default.action <SPAN
1306 {+change-x-forwarded-for{block}
1307 +deanimate-gifs {last}
1308 +fast-redirects {check-decoded-url}
1309 +filter {refresh-tags}
1310 +filter {img-reorder}
1311 +filter {banners-by-size}
1313 +filter {jumping-windows}
1314 +filter {ie-exploits}
1315 +hide-from-header {block}
1316 +hide-referrer {forge}
1317 +session-cookies-only
1318 +set-image-blocker {pattern}
1321 { -session-cookies-only }
1327 In file: user.action <SPAN
1334 (no matches in this file)</PRE
1339 > This is telling us how we have defined our
1341 HREF="actions-file.html#ACTIONS"
1347 which ones match for our test case, <SPAN
1351 Displayed is all the actions that are available to us. Remember,
1355 > sign denotes <SPAN
1365 >. So some are <SPAN
1372 >. Each example we try may provide a slightly different
1373 end result, depending on our configuration directives.</P
1379 > file. The large, multi-line
1380 listing, is how the actions are set to match for all URLs, i.e. our default
1381 settings. If you look at your <SPAN
1384 > file, this would be the
1385 section just below the <SPAN
1388 > section near the top. This
1389 will apply to all URLs as signified by the single forward slash at the end
1390 of the listing -- <SPAN
1395 > But we have defined additional actions that would be exceptions to these general
1396 rules, and then we list specific URLs (or patterns) that these exceptions
1397 would apply to. Last match wins. Just below this then are two explicit
1400 >".google.com"</SPAN
1401 >. The first is negating our previous
1402 cookie setting, which was for <A
1403 HREF="actions-file.html#SESSION-COOKIES-ONLY"
1406 >"+session-cookies-only"</SPAN
1409 (i.e. not persistent). So we will allow persistent cookies for google, at
1410 least that is how it is in this example. The second turns
1418 HREF="actions-file.html#FAST-REDIRECTS"
1421 >"+fast-redirects"</SPAN
1424 action, allowing this to take place unmolested. Note that there is a leading
1427 >".google.com"</SPAN
1428 >. This will match any hosts and
1429 sub-domains, in the google.com domain also, such as
1432 >"www.google.com"</SPAN
1435 >"mail.google.com"</SPAN
1439 >"www.google.de"</SPAN
1440 >! So, apparently, we have these two actions
1441 defined as exceptions to the general rules at the top somewhere in the lower
1449 > is referenced somewhere in these latter sections.</P
1454 > file, we again have no hits.
1455 So there is nothing google-specific that we might have added to our own, local
1456 configuration. If there was, those actions would over-rule any actions from
1457 previously processed files, such as <TT
1464 > typically has the last word. This is the
1465 best place to put hard and fast exceptions,</P
1467 > And finally we pull it all together in the bottom section and summarize how
1471 > is applying all its <SPAN
1491 +change-x-forwarded-for{block}
1492 -client-header-filter{hide-tor-exit-notation}
1493 -content-type-overwrite
1494 -crunch-client-header
1495 -crunch-if-none-match
1496 -crunch-incoming-cookies
1497 -crunch-outgoing-cookies
1498 -crunch-server-header
1499 +deanimate-gifs {last}
1500 -downgrade-http-version
1503 -filter {content-cookies}
1504 -filter {all-popups}
1505 -filter {banners-by-link}
1506 -filter {tiny-textforms}
1507 -filter {frameset-borders}
1508 -filter {demoronizer}
1509 -filter {shockwave-flash}
1510 -filter {quicktime-kioskmode}
1512 -filter {crude-parental}
1513 -filter {site-specifics}
1514 -filter {js-annoyances}
1515 -filter {html-annoyances}
1516 +filter {refresh-tags}
1517 -filter {unsolicited-popups}
1518 +filter {img-reorder}
1519 +filter {banners-by-size}
1521 +filter {jumping-windows}
1522 +filter {ie-exploits}
1529 -handle-as-empty-document
1531 -hide-accept-language
1532 -hide-content-disposition
1533 +hide-from-header {block}
1534 -hide-if-modified-since
1535 +hide-referrer {forge}
1538 -overwrite-last-modified
1539 -prevent-compression
1541 -server-header-filter{xml-to-html}
1542 -server-header-filter{html-to-xml}
1543 -session-cookies-only
1544 +set-image-blocker {pattern} </PRE
1549 > Notice the only difference here to the previous listing, is to
1552 >"fast-redirects"</SPAN
1555 >"session-cookies-only"</SPAN
1557 which are activated specifically for this site in our configuration,
1558 and thus show in the <SPAN
1560 >"Final Results"</SPAN
1563 > Now another example, <SPAN
1565 >"ad.doubleclick.net"</SPAN
1575 > { +block{Domains starts with "ad"} }
1578 { +block{Domain contains "ad"} }
1581 { +block{Doubleclick banner server} +handle-as-image }
1582 .[a-vx-z]*.doubleclick.net</PRE
1587 > We'll just show the interesting part here - the explicit matches. It is
1588 matched three different times. Two <SPAN
1594 >"+block{} +handle-as-image"</SPAN
1596 which is the expanded form of one of our aliases that had been defined as:
1599 >"+block-as-image"</SPAN
1601 HREF="actions-file.html#ALIASES"
1607 the first section of the actions file and typically used to combine more
1608 than one action.)</P
1610 > Any one of these would have done the trick and blocked this as an unwanted
1611 image. This is unnecessarily redundant since the last case effectively
1612 would also cover the first. No point in taking chances with these guys
1613 though ;-) Note that if you want an ad or obnoxious
1614 URL to be invisible, it should be defined as <SPAN
1616 >"ad.doubleclick.net"</SPAN
1618 is done here -- as both a <A
1619 HREF="actions-file.html#BLOCK"
1633 HREF="actions-file.html#HANDLE-AS-IMAGE"
1636 >"+handle-as-image"</SPAN
1639 The custom alias <SPAN
1643 >+block-as-image</TT
1646 simplifies the process and make it more readable.</P
1648 > One last example. Let's try <SPAN
1650 >"http://www.example.net/adsl/HOWTO/"</SPAN
1652 This one is giving us problems. We are getting a blank page. Hmmm ...</P
1661 > Matches for http://www.example.net/adsl/HOWTO/:
1663 In file: default.action <SPAN
1673 +change-x-forwarded-for{block}
1674 -client-header-filter{hide-tor-exit-notation}
1675 -content-type-overwrite
1676 -crunch-client-header
1677 -crunch-if-none-match
1678 -crunch-incoming-cookies
1679 -crunch-outgoing-cookies
1680 -crunch-server-header
1682 -downgrade-http-version
1683 +fast-redirects {check-decoded-url}
1685 -filter {content-cookies}
1686 -filter {all-popups}
1687 -filter {banners-by-link}
1688 -filter {tiny-textforms}
1689 -filter {frameset-borders}
1690 -filter {demoronizer}
1691 -filter {shockwave-flash}
1692 -filter {quicktime-kioskmode}
1694 -filter {crude-parental}
1695 -filter {site-specifics}
1696 -filter {js-annoyances}
1697 -filter {html-annoyances}
1698 +filter {refresh-tags}
1699 -filter {unsolicited-popups}
1700 +filter {img-reorder}
1701 +filter {banners-by-size}
1703 +filter {jumping-windows}
1704 +filter {ie-exploits}
1711 -handle-as-empty-document
1713 -hide-accept-language
1714 -hide-content-disposition
1715 +hide-from-header{block}
1716 +hide-referer{forge}
1718 -overwrite-last-modified
1719 +prevent-compression
1721 -server-header-filter{xml-to-html}
1722 -server-header-filter{html-to-xml}
1723 +session-cookies-only
1724 +set-image-blocker{blank} }
1727 { +block{Path contains "ads".} +handle-as-image }
1740 configuration! But we did not want this at all! Now we see why we get the
1741 blank page. It is actually triggering two different actions here, and
1742 the effects are aggregated so that the URL is blocked, and <SPAN
1746 to treat the block as if it were an image. But this is, of course, all wrong.
1747 We could now add a new action below this (or better in our own
1751 > file) that explicitly
1760 HREF="actions-file.html#BLOCK"
1769 > in them (remember, last match in the configuration
1770 wins). There are various ways to handle such exceptions. Example:</P
1785 > Now the page displays ;-)
1786 Remember to flush your browser's caches when making these kinds of changes to
1787 your configuration to insure that you get a freshly delivered page! Or, try
1793 > But now what about a situation where we get no explicit matches like
1803 > { +block{Path starts with "ads".} +handle-as-image }
1809 > That actually was very helpful and pointed us quickly to where the problem
1810 was. If you don't get this kind of match, then it means one of the default
1811 rules in the first section of <TT
1815 the problem. This would require some guesswork, and maybe a little trial and
1816 error to isolate the offending rule. One likely cause would be one of the
1818 HREF="actions-file.html#FILTER"
1824 These tend to be harder to troubleshoot.
1825 Try adding the URL for the site to one of aliases that turn off
1827 HREF="actions-file.html#FILTER"
1843 .worldpay.com # for quietpc.com
1865 >{ -filter -session-cookies-only }</TT
1868 Or you could do your own exception to negate filtering:</P
1878 # Disable ALL filter actions for sites in this section
1886 > This would turn off all filtering for these sites. This is best
1891 exceptions. Note that when a simple domain pattern is used by itself (without
1892 the subsequent path portion), all sub-pages within that domain are included
1893 automatically in the scope of the action.</P
1895 > Images that are inexplicably being blocked, may well be hitting the
1897 HREF="actions-file.html#FILTER-BANNERS-BY-SIZE"
1900 >"+filter{banners-by-size}"</SPAN
1904 that images of certain sizes are ad banners (works well
1909 >most of the time</I
1911 > since these tend to be standardized).</P
1919 > is an alias that disables most
1920 actions that are the most likely to cause trouble. This can be used as a
1921 last resort for problem sites.</P
1931 # Handle with care: easy to break
1933 mybank.example.com</PRE
1942 >Remember to flush caches!</I
1948 > reference lacks the TLD portion (e.g.
1952 >). This will effectively match any TLD with
1956 > in it, such as <TT
1958 >mail.google.de.</TT
1960 just as an example.</P
1962 > If this still does not work, you will have to go through the remaining
1963 actions one by one to find which one(s) is causing the problem.</P
1971 SUMMARY="Footer navigation table"