Movieclip mouse panning - almost there!

it’s late, and I’m exhausted… for some reason this isn’t panning the entire length of my movieclip (it’s length is dynamic). This is using tweener for the easing…

moveList = function () {
	mousePosY = mcPan.listNews.mask._ymouse;
	maskHeight = mcPan.listNews.mask._height;
	maskPosY = mcPan.listNews.mask._y;
	moveClip = mcPan.listNews.list;

	if (mcPan.listNews.mask.hitTest(_root._xmouse, _root._ymouse, false)) {
		var ypercent = mousePosY/maskHeight;
		Tweener.addTween(moveClip,{_y:maskPosY-moveClip._height*ypercent, time:1, transition:'easeOutExpo'});