When a player gets knocked out, don't focus on the button. What's important is that all players pay their blinds. If the player on your left, i.e. the big blind, got knocked out instead of the dealer, there would only be a big blind in the next hand since you already posted the small blind and can't be forced to do it again. If that's the case, the dealer button stays for one more hand and player 3 posts big blind. The forthcoming hand you become the dealer and the game can go on as usual.