function showDialog(url, w, h) {
	var l = (screen.width - w) / 2;
	var t = (screen.height - h) / 2;
	var win = window.open(url, Math.round(Math.random()*10000000000), "height="+h+",width="+w+",left="+l+",top="+t+",scrollbars=no,status=yes,toolbar=no,titlebar=no,menubar=no,resizable=no,location=no");
	if(win) win.focus();
}