I think one of the other responses nailed it: the ^ operator in javascript ... Bitwise XOR a ^ b Returns a one in a bit position if bits of one but not both operands are one. from http://developer.netscape.com/docs/manuals/communicator/jsref/ops.htm#10 42498 sgd -- work: http://ti3.com/ non: http://thinksafely.org/ > -----Original Message----- > From: Michael Galvin [mailto:mpgalvin at eircom.net] > > Right, Math.round is probably more technically correct, but > it certainly > isn't the cause of the massive difference between the 2 results. ;) >