As noted early in this book, different browsers don't always display HTML in the same way. What's worse, really old browsers don't even understand some of the code that Dreamweaver can produce, because Dreamweaver may conform to HTML or CSS standards that were developed only in recent years.
The best way to ensure that visitors see your site the way you intend it is to frequently preview your pages in as many browsers on as many computers as possible. In this way, you can identify and fix problems early.
But if you don't happen to have old computers with old browsers lying around your basement, Dreamweaver can identify elements of a page that won't work in older browsers, or that may be supported by only a single browser. For example, the <layer> tag works only in Netscape 4.
The Netscape <layer> tag is not the same as Dreamweaver layers (Chapter 8).
Dreamweaver's Check Browser Support feature checks the HTML and CSS code of pages you've selected and tells you if you've used code that doesn't work in various browsers: Internet Explorer, Firefox, Safari, Netscape Navigator, Mozilla, and Opera.
You can even specify which versions of the browsers you'd like to test, all the way back to the 3.0 version of Internet Explorer for Windows (which is still being used by Jason P. O'Gillicuddy of Muddy Ditch, Kansas).
In fact, you can have Dreamweaver automatically check browser support each time you open a file. If the program detects an error, it displays a yellow warning ...