Are you a web application developer or do you enjoy customizing your personal website?  If you want your sites to have a high level of interactivity such as those found in Google's web apps or if you want your site to behave more like a standard local program sitting on your hard drive, you need to check out the awesome JavaScript library called: jQuery. It's very easy to set up.  Just download the library called "jquery-1.3.2.min.js" from http://jquery.com/.  Then include that file in your web page's source.  Once it's included in your web page, you can write simple JavaScript that can do very complex things including Ajax.  The framework makes writing scripts much easier.  For example, say you want a text box to have a value of "HelloWorld".  You can see how the old way below is cumbersome compared to the concise jQuery way. Old way: document.frmForm.textbox.value='HelloWorld'; jQuery way: $("#textbox").val("HelloWorld"); With jQuery, you also don't have to worry about your JavaScript working with different browsers as the library is cross-browser compatible.  You can write one set of JavaScript and be fairly sure that it'll work on all browsers. Check out some demos here: http://jqueryui.com/demos/ Download and learn from here: http://jquery.com