//--------- sniff OS and browser ---------

var agt;            //user agent string
var ie;             //Internet Explorer, boolean
var nc;             //Netscape Nav/Communicator
var ver;			//browser version, as Integer
var win             //Windows OS, boolean
var mac;            //Mac OS, boolean

agt = navigator.userAgent.toLowerCase();
ie = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
nc = (navigator.appName.indexOf("Netscape") != -1);
ver = parseInt(navigator.appVersion);
win = ((agt.indexOf("win")!=-1) || (agt.indexOf("32bit")!=-1));
mac = (agt.indexOf("mac")!=-1);