Unless you are using a CGI script to detect which browser they are using, you will not be able to modify your site on the fly like that. You will need to consider your menu placement well. Any time you have a long page, it is very useful if you include a link back to the top at the bottom of your page. Many people use browsers, such as WebTV, Lynx, etc., that do not scroll as easily as Netscape Navigator, and MS Internet Explorer. Browsers One of the things you must decide is which browsers you want to support.
Every browser is different and each has it's own quirks.
If you design your website to look great in MS Internet Explorer, it will probably be ugly in Netscape Navigator, and vice versa. It is important to choose which browsers you are going to support, then try your site with each of them. I have found that by following some simple rules, you can support the vast majority of browsers. Don't use extensions added by a single company unless you only want to support their browser. Second, always be as strict as possible with your HTML coding.