increase drop area

Hi!

I want to increase a dropzone success detection area from html5 code.

Teh working code is here: 

root.check = function()
{
	var spot = slots.getObjectUnderPoint(pieces.target.x, pieces.target.y);
	
	if (!spot)
	{
		root.onMiss();
		return;
	}
	
	root.slot = spot.parent;
		
	if (root.slot)
	{		
		if (pieces.target.name === root.slot.name)
		{
			root.onMatch();
			
			if (pieces.count === pieces.children.length)
				root.onWin();
		}
		else
			root.onMiss();
		
		root.slot = null;
	}
	else
		root.onMiss();
};

How can i extend the sucess area, so that you don't have to throw it exactly right to succeed?

Thanx!