Illegal division by zero means just that - you can't have zero as the denominator of a fraction or the second operand of a division, because that would be undefined. Computers don't deal well with this, just like humans don't. You should check to see if a number is zero before trying to divide by it. Don't feel bad, though, abut having this type of error crop up. There's a potential divide-by-zero error in Benchmark.pm (as ships with 5.6.0 anyway -- see p5p or bugs.perl.org for discussion of that). Chris