function sipop(URL,WIDTH,HEIGHT) { 

	//if (navigator.appVersion.indexOf('Mac') != -1) {
	//WIDTH -= 40;
	//HEIGHT -= 50;
	//}
	
	if (screen.height < 700) {
		vpos = 0;
	} else {
		vpos = (screen.height/2)-(HEIGHT/2);
	}
	
	xpos = (screen.width/2)-(WIDTH/2);
	
	var features = "width=" + WIDTH + ",height=" + HEIGHT + ",top=" + vpos +",left=" + xpos + ",resize=false,scrollbars=no";
	var windowname = URL.substr(0,5);
	
	newpop = window.open(URL,windowname,features);
	
	
	if (navigator.appVersion.indexOf('Mac') != -1 && screen.height < 700) {
		newpop.resizeTo(WIDTH,HEIGHT);
		//newpop.moveTo(left,0);
	}
	
	newpop.focus();

}