function checkBrowser()
{  b = navigator.appName ;
   v = navigator.appVersion.split(" ") ;
   if (b == 'Netscape' && v[0] == "5.0")
   {alert("You are using Mozilla Firefox as your browser.\n\nThis Form does does not work with this browser.\nIf you wish to use this form you should use Internet Explorer Version 5 or later.") ;
      return false ;
   }
   else return true ;
}