On Thu, 12 Aug 2010 15:33:15 +0200, "Charlotte E"
wrote:

As an aside, it is a bit shorter (eliminates the IF statement) to
write your UDF this way:

=====================
Function FTE(Hours, Optional Periods = 26.1)
Application.Volatile
FTE = Hours / (Periods * 70)
End Function
=====================

Problem with that solution is that the function is not as 'robust' - the
user can force an error by entering af negative number of periods!

I think you should use this instead, which will trap such errors:

Function FTE(FTE_Hours, Optional FTE_Periods As Double = -1)
Application.Volatile
If FTE_Periods <= 0 Then FTE_Periods = 26.1
FTE = FTE_Hours / (FTE_Periods * 70)
End Function


CE


Of course, the user did not specify that he wanted to exclude a
negative number for the Periods variable.

However, if you feel data entry requires validation, why limit the
validation to just the Periods value, and why limit that to only
positive values?