[eof]

I think you should confront the kid too. Judge his reaction etc. I think letting him keep it isn't such a bad idea if he tells the whole truth. He probably thinks you wouldn't notice. However, the way you tell the story i think its very very possible you actually were shorted or spent it on accident. I think you should probably be able to tell if the kid is lying, if you are sure he is lying to you, tell his parents.. if you aren't sure then let it pass, apologize etc.