This message just came in from a happy reader: Duncan, It's Michael ... from the States. I used the formulas you suggested in your website to create a spreadsheet in excel for my data analysis on my Dissertation. I showed my Major Professor your work and how I created a spreadsheet from what you had posted. Needless to say he was quite impressed. If you do not mind, when I publish my work, I would like to acknowledge you in the acknowledgment section of my dissertation. I do research in the area of hormonal response to stress over time. Your website has made this process much more simple. Thank you again, Michael ... B.S., M.S., CSCS, PhD. candidate Isn't that nice? See the safe hands you're in at www.duncanwil.co.uk? DW