Here's one... don't assume that ~0 (all 1s) == -1. On a ones-complement machine -1 is (of course) ~1. -- Peter da Silva, Ferranti International Controls Corporation, sugar!ficc!peter. "You made a TIME MACHINE out of a VOLKSWAGEN BEETLE?" "Well, I couldn't afford another deLorean." "But how do you ever get it up to 88 miles per hour????"