Very true. I was a bit hasty in answering. A better syntax would be:
Function AutoFail(CSEVal97 as Integer, CSEVal98 as Integer, CSEVal99 as Integer) as Integer
If CSEVal97 = 0 Then
AutoFail = 0
Else
AutoFail = CSEVal98 + CSEVal99
End if
End function
You should test your input for nulls before calling the function.