Tween action script trouble

:crying: i need to make a tween in flash that repeats its self when it finishes. it needs to be 1 frame and be in action script 2.0 i have managed to make the tween but it wont play again.

Could any one give me and hand

Thanks
Stupid Saint

var tw = new mx.transition.tween(args)
tw.onMotionFinished = function(){
this.start()
}
http://livedocs.adobe.com/flash/8/main/wwhelp/wwhimpl/common/html/wwhelp.htm?context=LiveDocs_Parts&file=00001502.html