I want to be a waitress or bartender but i'm mad with dealing with money?

Are there any waitress's out there that could tell me how the end of the night works when people leave there bill do you ask if they need money back or what? If they put to much do you take it or give back? %26amp; do they normally do it on the cash register or in there head/ does it actually say what to give back? -thanx|||Hunny pie, If you best be bad dealing wit muney den you can be a waitress! jusss as simple as dat hoe. You are going to loose all the money and make the resterant run out of BIZ. so sorry