I need a key for my file cabinet..?

I won a file cabinet in an auction that has a lock but no key. It's not locked but I would like to get a key made for it so that I can utilize the lock. One of the websites that I went to suggested if I have the key lock number (usually printed on the front of the lock) they could make a key for me. There is no such number on the lock so they suggested that I call a locksmith. Any suggestions as to how I can get a key or a whole new embly for my file cabinet without having to hire a locksmith?