Hey there, 

Basically what I am doing is I have a form that has two text fields that can't sum above 100. So when the first text field number is entered, the script below deducts 100 to it and adds that number to the second text field. That works just fine ACCEPT for it is now negative number. So all I need to do is add 100 to it or use math.ads. Just no clue on the proper syntax to get $txtInterest to be a positive number.