Making Waves:
DHTML (Dynamic HTML)

If HTML describes the structure of informational content and CSS describes its style, then DHTML captures the dynamics of both style and content. DHTML is best known for making graphics fly across the Web page. But DHTML not only adds the “dazzle” to the razzle-dazzle of the World Wide Web, it also makes the Web more useful with its ability to provide interactive content tailored to users’ needs.

As Web authors have grown proficient in DHTML, the dynamics of content has come into play. User-specified needs can be collected and processed on the client’s Web page, speeding up access and allowing ever more focused content. E-commerce sites may experience better sales with a customized product selection. Knowledge bases can become more effective in pointing users to answers. And in online Help systems, where the user is often not even connected to a server, dynamic HTML lets the author provide on-the-fly customizations for readers at different levels and in different situations.

Although many of these options are available through diverse technologies, DHTML scripting and style sheets generally offer a better solution than other approaches to interactivity. Because the DHTML technologies are native to the Web, they are small and fast and do not require any downloads or plug-ins. DHTML also beats out CGI: as a client-side technology, DHTML is faster and less complex to implement. And it is far simpler to write!

NOTE:
All code in this section is designed for use in HTML Help, not for general HTML usage. Specifically, where conflicts exist, the code is Internet Explorer-specific; most of it does not work in Netscape Navigator or Communicator.