My horn goes off when I crank up the car

What is your question?

When I turn the car on, the horn give one loud beep. Sometimes it stops if I hit the steering a couple times, other times I have to turn it off an on, hit, hit before it stops. It will also start blowing randomly when I am driving espcially if I turn left. It seems to get worse in cold weather. One Indy did not want to touch it because he said he'd have to change the airbag also which is expensive.. Really? Help!