function sub_window(w_name,w,h){
	sub = window.open("contents/city/"+w_name,"_blank",			"toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,width="+w+",height="+h);
	var x = (screen.width - w)/2;
	var y = (screen.height - h)/2-50;
	sub.moveTo(x,y);
}