HELP! 98 honda prelude check engine light...?

Well before you run into trouble or go out and get ripped off, do 1 very simple thing, That is take the gas cap off and put it on tightly. There are times when air gets into the gas and somehow the sytem check engine light appears. I hope that is the only problem. If that is not it be sure you have enough oil, than if that is Ok you may want to bring it to a mechanic