Thanks Andrew and Les for your responses. My client has solved the problem -
there was a Solver Add-In that had to be enabled (under Options/Add-Ins).
There was also a reference to a user-defined function Gasvisc2(pavg, tave,
sg, Co2, n2, h2s) in one of the macros but the function source wasn't
included in the macro module.

Regards, ...Bruce

"Andrew Taylor" wrote:

This can happen if you've inadvertently used the name of an
existing built-in function, e.g.

Function Now(s As String)
Now = 0
End Function

VBA doesn't complain about the name clash but the
Insert/Function dialog will use the built-in function.





BruceInCalgary wrote:
I have a user defined VBA function in my Excel spreadsheet. I do an Insert
- Function and then I select the user-defined function from the function
list. Excel should then display a Function Arguments form prompting for the
parameters for this function, but instead, Excel displays the mesasge "This
function takes no arguments.". This works on some PCs but not others and the
problem occurs with Excel 2002 and Excel 2003. I have looked at the
references in VB but there doesn't seem to be anything missing. Any help
would be greatly appreciated!

Regards, ....Bruce