Removing Gasoline Smell from Car?

I spilled gas in the front seat of the car. How can I get rid of the smell? I need something more than "open the windows and air it"; that's been done and was not much help. I also put newspaper on the seat and put a heavy rock on top, hoping to absorb the gas, that helped some, but not much. Anybody have any ideas? Thanks.

By SharonH