Raising After an All-In

[vince522]

I am in a home game and we have decided to allow side pots to bring our game closer to tournament specs. I cannot find an answer to the following question (I hope I am not being stupid about it).

Three players left after the flop. A, B and C.
A has 200 chips.
B has 50 chips.
C is chip leader with 500 chips.

A acts first and bets 20. B calls and goes all-in with remaining 30 chips. C calls, for 50 chips, and raises A 50 more chips in a side pot. What happens if A decides he does not want to call C's side raise(he just wanted to call B's all-in)? Does A lose all his bet chips or is he still involved with B's all-in?

[Poker_Vendetta]

He would have to call the most recent raise, so he would either call the extra fifty or fold. It's like this: A raises to 20, B reraises all-in to 50, C reraises to 100--thus he must call 80 I guess. Is this incorrect anyone?

[Adamm]

If A decides not to call C's raise, C takes back 50 and B and C flip em and the winner takes the 150 pot. A is not involved with that pot.