Many online services have stopped supporting Internet Explorer 6 and when a user tries to access them with the browser sent him to the information page, where the offer to upgrade IE to latest version or choose another browser. Here is my easiest solution for this:
<html> <head> <!--[if lt IE 7]> <script type="text/javascript" charset="utf-8"> window.location = 'location_of_your_no_ie6_page'; </script> <![endif]--> ... </head> ... </html>
It used nothing, but IE conditional comments, so it’s very compact and fast ’cause every browser except IE6 and lower just ignores this code.