DHTML Tutorials

HTML is a good tool for publishing small file size documents over the Internet. However, HTML in its traditional form is not powerful enough to create the interactive and multitude-rich documents that today’s commercial web sites demand.In addition, a standard HTML document cannot specify that text and images be located at exact coordinates, on top of each other, or even that the text be displayed in a particular point size (Heinle). Most computer programming languages have more functionality than HTML. In order to combine these two programming languages together to be more powerful, Dynamic HTML emerged.

Dynamic HTML was first developed in the mid-1990s, Netscape and Microsoft had differing ideas about what technologies should be used to make HTML more dynamic.The Specification were as follows:

Netscape-Specific DHTML

Netscape brought several new technologies to the table, hoping to create more dynamic Web pages. Unfortunately, these technologies never became standard because CSS does most of the same things and is endorsed by the W3C.JavaScript Style Sheets (JSS) were introduced in Navigator 4 as Netscape's alternative to CSS. Like CSS, JSS lets you define how HTML tags display their content, but JSS uses JavaScript syntax. The only browser that supports JSS, however, is Navigator 4. Not even the latest versions of Netscape or Mozilla support this technology.

In addition, Netscape offers HTML layers, which, like CSS positioning controls, Which let you control the position and visibility of elements on the screen.

Microsoft-Specific DHTML

Much of the Microsoft-specific DHTML is based on proprietary Microsoft technologies, such as ActiveX. Because ActiveX is owned by Microsoft, it is unlikely that it will ever be a cross-browser technology. In addition, legal actions have called the use of ActiveX controls into question and at the very least will make them more difficult to implement.

Microsoft also introduced dynamic visual filters (which use ActiveX controls) that let you add visual effects to graphics and text in your document. The problem is that these filters are not standard on all browsers, and aren't even supported in all versions of Internet Explorer.