I have a points calculator as part of one of my forms, it works fine except where users change their mind which seems to happen regularly. So the users pick a subject, the level they study at (higher or lower) and the grade they received A, B etc and each grade has a value which is used in a calculation field to give them a total points value.
So all this works but users sometimes make a mistake on the higher and lower choice and go back and change that value. So what I want to do is clear out the existing value if the higher and lower option is changed and then adjust the points calculation value. Any ideas on how I could do this?