// Open popup window
function open_window(url_link, window_name, window_width, window_height)
{
	//window_height = screen.height;
	screen_width = screen.width;
	screen_height = screen.height;

	//window_width = 290;
	//window_height = 170;
	//window_width = screen_width - 10;
	//window_height = screen_height - 57;

	position_top = (screen_height - 20 - window_height) / 2;
	position_left = (screen_width - 10 - window_width) / 2;

	window_options = 'toolbar=0,scrollbars=yes,location=0,statusbar=0,menubar=0,resizable=0,width=' + window_width + ',height=' + window_height + ',left=' + position_left + ',top=' + position_top + ',leftmargin=0';
	window.open(url_link, window_name, window_options);
}