Not a case of 'blind faith' just that the program has the same formulas that we used and gives the info without going through all the math work. I guess if he wanted to learn the formulas then a calculator would take out all the fun, then again if he only wanted the info it would work out OK. I'm an engineer and welcomed the use of slide rules (remember those?) and later calculators and computers to solve my design parameters. Never had one lie, but I did punch the wrong button from time to time. I do apologize for trying to help, thinking he only wanted the data.

quint