var Op = (navigator.userAgent.indexOf('Opera') != -1);
var NAV3 = (((navigator.appName.indexOf('Netscape') != -1) && (navigator.appVersion.substring(0,1) == 3) && !Op));
var NAV4 = ((navigator.appName.indexOf('Netscape') != -1) && (navigator.appVersion.substring(0,1) == 4)); 
var NAV6 = ((navigator.appName.indexOf('Netscape') != -1) && (navigator.appVersion.substring(0,1) >= 5)); 
var IE = ((navigator.userAgent.indexOf('MSIE') != -1) || (navigator.userAgent == ""));
var WEBTV = (navigator.appName.indexOf('WebTV') != -1);
var DOM = (document.getElementById) ? true : false;
var IE4 = IE && !DOM;