−Welcome to JavaScript Essentials.
+<table border="0" cellspacing="0" width="100%">
+<tr>
+<td width="20%">[[JavaScript Essentials|Previous]]<td align="center">[[JavaScript Essentials|Table of Contents]]<td width="20%" align="right">[[Intended Audience|Next]]</td>
+<tr>
+<td width="20%">Table of Contents<td align="center"><td width="20%" align="right">Intended Audience</td>
+</table>
+<hr>
−Before JavaScript was created a typical web browsing experience consisted largely of displaying static pages of information. Any type of user interaction with a web page usually involved the browser sending information back to the web server where some type of server based script or other program would validate the user's data input. The server would then send back either a static error page if the user had entered invalid data or, assuming successful validation, return a static page to the web browser containing the results of the transaction. In addition, the lack of a mechanism to implement dynamic web page content and behavior dictated that an entirely new web page be loaded in order to display new information.
Exception encountered, of type "Error"
[0f1512ce] /index.php?diff=cur&oldid=888&title=About_this_Book Error from line 434 of /var/www/techotopia/includes/diff/DairikiDiff.php: Call to undefined function each()
Backtrace:
#0 /var/www/techotopia/includes/diff/DairikiDiff.php(544): DiffEngine->diag()
#1 /var/www/techotopia/includes/diff/DairikiDiff.php(344): DiffEngine->compareSeq()
#2 /var/www/techotopia/includes/diff/DairikiDiff.php(227): DiffEngine->diffLocal()
#3 /var/www/techotopia/includes/diff/DairikiDiff.php(721): DiffEngine->diff()
#4 /var/www/techotopia/includes/diff/DairikiDiff.php(859): Diff->__construct()
#5 /var/www/techotopia/includes/diff/DairikiDiff.php(980): MappedDiff->__construct()
#6 /var/www/techotopia/includes/diff/TableDiffFormatter.php(194): WordLevelDiff->__construct()
#7 /var/www/techotopia/includes/diff/DiffFormatter.php(140): TableDiffFormatter->changed()
#8 /var/www/techotopia/includes/diff/DiffFormatter.php(111): DiffFormatter->block()
#9 /var/www/techotopia/includes/diff/DifferenceEngine.php(881): DiffFormatter->format()
#10 /var/www/techotopia/includes/diff/DifferenceEngine.php(797): DifferenceEngine->generateTextDiffBody()
#11 /var/www/techotopia/includes/diff/DifferenceEngine.php(728): DifferenceEngine->generateContentDiffBody()
#12 /var/www/techotopia/includes/diff/DifferenceEngine.php(662): DifferenceEngine->getDiffBody()
#13 /var/www/techotopia/includes/diff/DifferenceEngine.php(632): DifferenceEngine->getDiff()
#14 /var/www/techotopia/includes/diff/DifferenceEngine.php(453): DifferenceEngine->showDiff()
#15 /var/www/techotopia/includes/page/Article.php(797): DifferenceEngine->showDiffPage()
#16 /var/www/techotopia/includes/page/Article.php(508): Article->showDiffPage()
#17 /var/www/techotopia/includes/actions/ViewAction.php(44): Article->view()
#18 /var/www/techotopia/includes/MediaWiki.php(490): ViewAction->show()
#19 /var/www/techotopia/includes/MediaWiki.php(287): MediaWiki->performAction()
#20 /var/www/techotopia/includes/MediaWiki.php(714): MediaWiki->performRequest()
#21 /var/www/techotopia/includes/MediaWiki.php(508): MediaWiki->main()
#22 /var/www/techotopia/index.php(41): MediaWiki->run()
#23 {main}