var app=null;
if(navigator.appName == "Netscape" && document.layers != null && navigator.appVersion.charAt(0)=="4") app="N";
else if(navigator.appName == "Microsoft Internet Explorer" && document.all != null) app="E";
else if(navigator.appName == "Netscape" && document.getElementById != null && navigator.appVersion.charAt(0)=="5") app="N5";