My bad....

I was just looking for instances in which "no string" or a NULL
value is passed to the function. I'm thinking that the
"If myData = vbNullString" will be sufficient enough.

BTW, I'm a long time C++ programmer, so I developed a
habit of doing a lot of NULL error testing. VBA seems to
be more "type safe" when it comes to null strings, so I
kinda get the impression that I don't need to always check
for NULL strings, but I still wanted to know how to do it
anyways.

Thanks for the info.


"Mike H" wrote in message
...
Robert,

I missed the 'invalid' bit but you don't tell us what 'invalid' means.
Maybe
you mean a number?

Function Foo(ByVal myData As String)
If myData = vbNullString Or IsNumeric(myData) Then
Foo = "No string passed to function"
Exit Function
End If
' Do stuff
End Function
--