/*
 * Which browser do we have?
 */
var NN = (navigator.appName == "Netscape");
var NN2 = NN && (navigator.userAgent.indexOf("Mozilla/2") != -1);
var NN3 = NN && (navigator.userAgent.indexOf("Mozilla/3") != -1);
var NN4 = NN && (navigator.userAgent.indexOf("Mozilla/4") != -1);

var IE = navigator.userAgent.indexOf("MSIE") != -1;
var IE3 = navigator.userAgent.indexOf("MSIE 3") != -1;
var IE4 = navigator.userAgent.indexOf("MSIE 4") != -1;

var OPERA = navigator.userAgent.indexOf("Opera") != -1;

/*
 * Define some families
 */
var NN3plus = NN && (parseInt(navigator.appVersion) >= 3);
var NN4plus = NN && (parseInt(navigator.appVersion) >= 4);
var IE4plus = IE && (parseInt(navigator.appVersion) >= 4);

/*
 * Do we have style sheets?
 */
if (IE) var IEcss = document.all ? true : false;
if (NN) var NNcss = parent.document.layers ? true : false;
var CSS = (IEcss || NNcss || OPERA);

/*
 * Which OS are we using?
 */
var LINUX = navigator.userAgent.indexOf("Linux") != -1;
var WINDOWS = navigator.userAgent.indexOf("Windows") != -1;