var isMac = (navigator.userAgent.indexOf("Macintosh") != -1);
var isWin = (navigator.userAgent.indexOf("Windows 95") != -1 || navigator.userAgent.indexOf("Windows NT") != -1);
var isNS =  (navigator.appName == "Netscape");
var isIE =  (navigator.userAgent.indexOf("MSIE") != -1);
var ieWin = (navigator.userAgent.indexOf("MSIE") != -1 && (navigator.userAgent.indexOf("Windows 95") != -1 || navigator.userAgent.indexOf("Windows NT") != -1));