This might not be of much help but my car's SRS light comes on when I put something lighter than a person - such as a backpack or books - on the passenger front seat.  If I remove the item, the light goes off.

The sensor underneath the seat might be faulty.  You need to get that chacked.  But I suppose, as Nayasadak suggested, going first to Autozone for free diagnosis might be prudent.