function Is() {
	var agent = navigator.userAgent.toLowerCase();
	this.major = parseInt(navigator.appVersion);
	this.minor = parseFloat(navigator.appVersion);
	this.ns  = ((agent.indexOf('mozilla')!=-1) && ((agent.indexOf('spoofer')==-1) && (agent.indexOf('compatible') == -1)));
	this.ns2 = (this.ns && (this.major == 3));
	this.ns3 = (this.ns && (this.major == 3));
	this.ns4 = (this.ns && (this.major >= 4));
	this.ie   = (agent.indexOf("msie") != -1);
	this.ie3  = (this.ie && (this.major == 2));
	this.ie4  = (this.ie && (this.major >= 4));
	this.op3 = (agent.indexOf("opera") != -1);
}

var is = new Is()

if(is.ns4) {
	doc = "document";
	sty = "";
	htm = ".document"
	xpos = "e.pageX";
	ypos = "e.pageY";
} else if(is.ie4) {
	doc = "document.all";
	sty = ".style";
	htm = ""
	xpos = "event.x";
	ypos = "event.y";
}