function PopupAndCenter_window(filename, x_size, y_size)
	{
		var left_position = (screen.width / 2) - (x_size / 2);
		var top_position = (screen.height / 2) - (y_size / 2);
		var window_option_arg = "width=" + x_size + ",height=" + y_size + ",left=" + left_position + ",top=" + top_position + ",resizable=no";
		var handler = window.open(filename, "NewWindow", window_option_arg);
	}