Thx for the thx, Susan. I'm glad it worked. The thing I learned whilst doing that was "STOP! Think about the math". By keeping the numbers simple, I was able to do it fairly easily (all parameters were entered numerically, not via the tools). And it only took me 30 mins to do it (including a couple of "oops: glad I saved recently" incidents). So I learned a lesson and managed to help at the same time! Insert feeling of warm, suffused glow here Cheers, Diolma