Peter T wrote:
I guess it depends on the OP's overall objective "I want to test to see if
the parameter has been included" and whether "included" means passed or
empty. The way I see it Len(arg) merely tests if the argument contains any
characters, or indeed is an empty string. It doesn't prove either way if the
optional argument was passed or 'is missing'.

Hi Peter

You're tight. It appears that even if it isn't passed, the variable is stored as an empty string ("")
For my routine Len(arg) is what I want. I assumed its results could be used within an If Then statement.
I've learnt something new today.

Thank You to all who replied.

Ta
Dave F.