Open the yellow pages and pick up your phone with your other hand. You
obviously dont have a clue, your water heater is 15 yrs old and you
dont need to hurt yourself or anyone else.
Call A Plumber,...........NOW!

I think you are being a bit harsh. These things are not rocket science;
sometimes the repairs are pretty simple, and with a little help he might
well be able to fix it himself.
I have fixed my dishwasher and clothes dryer myself with help I got here;
and if this were my water heater, I expect I could fix it if someone told me
what to look for. (I installed my own water heater 2 years ago, it just
isn't that difficult.)

Then again he might not be able to fix it himself; but you can give him the
benefit of the doubt. Or it is possible that the heater must replaced now
because the repair cannot be justified in a 15 yo heater.
Sadly, I do not know enough about water heaters to offer any help.