function GetMousePosition( e )
{
	// http://www.quirksmode.org/js/events_properties.html

	var posx = 0;
	var posy = 0;

	if ( !e )
	{
		var e = window.event;
	}

	if ( e.pageX || e.pageY )
	{
		posx = e.pageX;
		posy = e.pageY;
	}
	else
	{
		if ( e.clientX || e.clientY )
	 	{
			posx = e.clientX +
				document.body.scrollLeft +
				document.documentElement.scrollLeft;
			posy = e.clientY +
				document.body.scrollTop +
				document.documentElement.scrollTop;
		}
	}

	// posx and posy contain the mouse position relative to the document

	return [ posx, posy ];
}