Wife's Operation

I was in las Vegas, when a man walked up to me and "sir do you have a extra $20.00, my wife needs an operation that costs $1000.00. I have $980.00 and just need the last $20.00"

Well I thought about, when I ask the man, how will I know that you are going to walk into that casino and gamble it away.

Well the man replied "No sir... I have money for gambling."