// gets the mouse position relative to the image
function getPosition(objName, mouseX, mouseY)
{
	var x, y;
	var obj;
	var objX, objY;

	obj = document.getElementById(objName);	

	[objX, objY] = findObjectPosition(obj);

	// picture relative coordinates
	x = mouseX - objX;
	y = mouseY - objY;

	return [x, y];
}

// gets the mouse position
function findMousePosition(event)
{
	var x, y;
	
	if(event.pageX && event.pageY)
	{
		x = event.pageX;
		y = event.pageY;
	}
	else if(event.clientX && event.clientY)
	{
		x = event.clientX + (document.documentElement.scrollLeft ?
			document.documentElement.scrollLeft : document.body.scrollLeft);

		y = event.clientY + (document.documentElement.scrollTop ?
			document.documentElement.scrollTop : document.body.scrollTop);
	}

	return [x ,y];
}

// gets the position of the object
function findObjectPosition(obj)
{
	var curleft = curtop = 0;
	if (obj.offsetParent)
	{
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent)
		{
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}

	return [curleft,curtop];
}