Right of contribution. (a)  General rule.-- The right of contribution exists among joint tort-feasors. (b)  Payment required.-- A joint tort-feasor is not entitled to a money judgment for contribution until he

§ 8324.  Right of contribution. (a)  General rule.-- The right of contribution exists among joint tort-feasors. (b)  Payment required.-- A joint tort-feasor is not entitled to a money judgment for contribution until he has by payment discharged the common liability or has paid more than his pro rata share thereof. (c)  Effect of settlement.-- A joint tort-feasor who enters into a settlement with the injured person is not entitled to recover contribution from another joint tort-feasor whose liability to the injured person is not extinguished by the settlement.