detecting cursor position

Is there any function in javascript to detect cursor position?

 

function GetMouseCoords(e)
{
	e = (e) ? e : window.event;
	
	var x = 0;
	var y = 0;
	
	if(e.pageX)
	{
		x = e.pageX;
		y = e.pageY;
	}
	
	else if(e.clientX)
	{
		x = e.clientX + document.body.scrollLeft;
		y = e.clientY + document.body.scrollTop;
	}
	
	return new Array(x, y);
}

Code (markup):

I think that was more or less stolen from quirksmode.org.