Make em bounce

onClipEvent (load) {
_x = 0;
//_y = 0;
speed = 5;
}
onClipEvent (enterFrame) {
endX = _root._xmouse;
//endY = _root._ymouse;
_x += (endX-_x)/speed;
//_y += (endY-_y)/speed;
}

if i wanted to add a little bounce effect that when scrolled it went a hair past the destination but came back how would that look?