The VBA procedure `HandleError` presents an error from an Excel function in the standard Invantive layout.
Parameters:
- `functionName`: name of Excel function causing the error.
## Examples
`HandleError` is typically invoked from VBA using logic like:
```vba
Function MY_FUNC() As String
On Error GoTo Catch
'
MY_FUNC = "ANSWER"
Finally:
Exit Function
Catch:
HandleError "MY_FUNC"
End Function
```