If you use content that requires a newer browser, such as for layers, you can check for the browser version with Javascript. You can serve up different content depending on what browser the user has or doesn't have.
*note: browsers before Netscape 2.0 and Explorer
3.0 will not support this behavior and the detection won't work.
*note: this is great for layers. Layers shouldn't
work in browsers 3.0 and below so create an alternate link.
How do I check for Browser versions?
1. In the behaviors panel, select a browser version 3 and above.
2. In the document window, select the whole body tag, opening to closing, or
click on the work <body> in the bottom of the document window. You can
also check for a plugin from a link (an <a> tag) in case you are going
to a page with content that requires a plug-in.
3. In the Behaviors Panel select the Check Browser action.
4. In the dialog box that follows, select a browser version for Netscape and Explorer and others. If you are testing for layers, choose version 4.0 and above. For Frames, Netscaper is version 2.0 and up and Explorer is version 3.0 and up. Enter in a URL and an Alt (alternate) URL. Click o.k.
5. In the Behaviors Panel select an event from the pull down (ex. onLoad or onClick).