I think that's something like Accentuate The Positive, right? I don't know if he was first, but I'm pretty sure Bing Crosby did a popular version.
I'm fairly confident about that one, so I'll post new lyrics. I'll take 'em down if I'm wrong.
This was a #1 hit in 1976:
I couldn't really blame you if you turned and walked away
But with everything I feel inside, I'm asking you to stay