Which song reached #1 on the U.S in 1983 (after Air Supply turned it down). It hit again #1 on the Billboard Hot 100 in 1990?

I think you may be talking about "How Am I Supposed To Live Without You?", which went #1 in 1990 for Michael Bolton. Laura Branigan also had a hit with it in 1983, but her version didn't reach the top...it went as high as #12. It was, however, #1 on the Adult Contemporary chart.

You are right Jelp, a little mistake from my part. Thanx.