Need help with an Excel IF formula

[DiscoStu]

I'm just more concerned you're trying to do something else here than meets the eye If there are values already on the sheet you want to preserve, you'll need to put your IF somewhere else to avoid overwriting them. Generally it's not a good idea to let your users overwrite your formulas (you should lock them) - give them an input area for data, then lock your calculated fields.

It's OK, it's just my brother trying to avoid a load of data entry, I'll make sure he backs up before he inserts the formula.