//make sure user has IE4 or Netscape4 or higher
	var av = navigator.appVersion;
	var an= navigator.appName;
	var ie = an.indexOf("Microsoft") != -1;
	var nav = an.indexOf("Netscape") != -1;
	var version = -1;
	var win = (navigator.appVersion.indexOf("Windows") != -1) ? true : false;
	var mac = (navigator.appVersion.indexOf("Mac") != -1) ? true : false;
	
	if(ie)
	{
		var semi1 = av.indexOf("MSIE ")+5;
		var semi2 = av.indexOf(";", semi1);
		version = parseFloat(av.substring(semi1, semi2));
	}
	else if(nav)
	{
		version = parseFloat(av.substring(0, 2));
	}
	else
	{
		version = 3;
	}