Make your Web pages more dynamic without overburdening your server.
By Sheryl Canter
You can create an attractive, colorful Web page just using HTML. But without some scripting, the page will just sit there, unresponsive to user actions. Scripts can run either on the Web server (server-side scripting) or on the user's computer (client-side scripting).
Server-side scripts are best suited for delivering custom or dynamic content. But what if you want a Windows-like menu bar on your Web site, or an expandable tree? You could implement these interface elements in a server-side script, but there are serious disadvantages to doing it this way: Your interface will be sluggish and you will greatly increase the bandwidth used.
To stem the chaos, the W3C stepped in with a DOM standard for HTML and XML. DOM Level 1, which was completed in October 1998, focuses on basic navigation and manipulation functions. Level 2, completed in November 2000, adds support for XML namespaces, Cascading Style Sheets (CSS), and user interface events. Level 3, which is still under development, will offer enhanced XML support and other advanced features.
But defining a standard is not the same as getting vendors to use it. So far Mozilla, the open-source version of Netscape Navigator (www.mozilla.org) has the most compliant DOM support, implementing most of Level 2. Microsoft did not support the W3C standard until Internet Explorer 6, which supports Level 1. Adding to developer stress is the fact that Microsoft's current proprietary implementation has some nice features that the W3C version lacks, such as the innerHTML property, which represents all the character data between an element's starting and ending tag.