var detect = navigator.userAgent.toLowerCase();

check_user_agent();

function check_user_agent()
{
   var OS,browser,version,total,thestring;
   
   if (checkIt('konqueror')) {
      browser = "Konqueror";
      OS = "Linux";
   }else if (checkIt('safari')) {
      browser = "Safari";
   }else if (checkIt('omniweb')) {
      browser = "OmniWeb";
   }else if (checkIt('opera')) {
      browser = "Opera"
   }else if (checkIt('webtv')) {
      browser = "WebTV";
   }else if (checkIt('icab')) {
      browser = "iCab"
   }else if (checkIt('msie')) {
      browser = "Internet Explorer"
   }else if (!checkIt('compatible')) {
      browser = "Netscape Navigator"
      version = detect.charAt(8);
   }else{
      browser = "An unknown browser";
   }

   if (!OS) {
   
      if (checkIt('linux')) {
         OS = "Linux";
      }else if (checkIt('x11')) {
         OS = "Unix";
      }else if (checkIt('mac')) {
         OS = "Mac"
      }else if (checkIt('win')) {
         OS = "Windows"
      }else{
         OS = "an unknown operating system";
      }
   }

   if (OS == 'Mac' && browser == 'Internet Explorer') {
      document.location = '/upgrade.php';
   }
}

function checkIt(string)
{
   place = detect.indexOf(string) + 1;
   thestring = string;
   return place;
}