Spring loaded object

programming flash
1

Hey all
Have got this interia spring on a mc object
it springs and eases into its set value.
What I want it to do is spring larger than its final state and bounce back and forwth? any one lost yet?

onClipEvent (load) {
xDest = this._xscale;
}
onClipEvent (enterFrame) {
if (this._xscale != xDest) {
this._xscale += (xDest-this._xscale).2;
}
}
onClipEvent (load) {
yDest = this._yscale;
}
onClipEvent (enterFrame) {
if (this._yscale != yDest) {
this._yscale += (yDest-this._yscale).2;
}
}