function istIE4() { var x = false; if ((navigator.appName.toUpperCase()=='MICROSOFT INTERNET EXPLORER') && (navigator.appVersion.substring(0,1) * 1 > 3)) x = true; return x; }
function istFiFo() { var x = false; if ((navigator.appName.toUpperCase()=='NETSCAPE') && (navigator.appVersion.substring(0,1) * 1 > 4)&& (navigator.userAgent.toUpperCase().search('FIREFOX')!=-1)) x = true; return x; }