/**
 * Open a window and place it in the centre of the screen
 */

function openWindow(url_str, name_str, width, height)
{
	//if (popup) popup.close();
	var popup = window.open(url_str, name_str, 'toolbar=no,scrollbars=yes,status=no,resizable=no,width='+width+',height='+height);
	//popup.resizeTo(width, height);
	popup.moveTo((screen.width/2)-(width/2), (screen.height/2)-(height/2)-20);
	popup.focus();
};