Detecting Browser Vendor

var isNav4, isIE4
if (navigator.appVersion.charAt(0) 
    == "4") {
   if (navigator.appName 
       == "Netscape") {
      isNav4 = true
   } else if (navigator.appVersion.
              indexOf("MSIE") != -1) {
      isIE4 = true
   }
}

Speaker Notes