var AgntUsr = navigator.userAgent.toLowerCase();
var DomYes = document.getElementById ? 1 : 0;
var NavYes = 
        AgntUsr.indexOf('mozilla') != -1 && AgntUsr.indexOf('compatible') == -1
        ? 1 
        : 0;
var ExpYes = AgntUsr.indexOf('msie') != -1 ? 1 : 0;
var OprYes = AgntUsr.indexOf('opera') != -1 ? 1 : 0;
var Opr6OrLess = 
        window.opera && navigator.userAgent.search(/opera.[1-6]/i) != -1; 
var DomNav = DomYes && NavYes ? 1 : 0;
var DomExp = DomYes && ExpYes ? 1 : 0;
var Nav4 = NavYes && !DomYes && document.layers ? 1 : 0;
var Exp4 = ExpYes && !DomYes && document.all ? 1 : 0;