Question about Backcourt

[jka347]

I was playing with some friends the other day and this came up. The ball was already established in the frontcourt, and was passed to a player running in from the backcourt. He jumped from the backcourt, caught the ball, landed in the frontcourt. Is this a violation?

I thought it was, but others insisted it was not. I thought you had to have your feet down in the front court first. Anyway, couldn't find anything explicit in the nba rules about this situation.