var browserName=navigator.appName; 
var browserVer=parseInt(navigator.appVersion); 
var ffversion=0;
if (/Firefox[\/\s](\d+\.\d+)/.test(navigator.userAgent)){ //test for Firefox/x.x or Firefox x.x (ignoring remaining digits);
 ffversion=new Number(RegExp.$1) // capture x.x portion and store as a number
}

if ((browserName=="Netscape" && ffversion>=2) || (browserName=="Microsoft Internet Explorer" && browserVer>=7)) 
  version="n3"; 
else 
  version="n2"; 

if (version=="n2") {
  document.write('<div class=\"bannerTop\">ALERT!</div>')
  document.write('<div class=\"bannerBottom\">This website is optimized for the latest versions of <a href=\"#\" onclick=\"window.open(\'http://www.mozilla.com/en-US/firefox/\');\"  class=\"fadeMenu\">Firefox</a> and <a href=\"#\" onclick=\"window.open(\'http://www.microsoft.com/windows/downloads/ie/getitnow.mspx\');\"  class=\"fadeMenu\">Explorer</a>. <br />Please upgrade your browser.</div>')
}

//  document.write(ffversion)
//  document.write(browserName)
//  document.write(navigator.appVersion)
//  document.write(navigator.userAgent)