var NAV6 = (parseInt(navigator.appVersion) >= 5 && navigator.appName == "Netscape") ? 1 : 0;
var NAV4 = (navigator.appName.indexOf("Netscape") >= 0 &&  parseFloat(navigator.appVersion) >= 4) ? 1 : 0;
var IE4 = (document.all) ? 1 : 0;
var IE5 = (IE4 && navigator.appVersion.indexOf("5.") >= 0) ? 1 : 0;