Public Function IsSheetNameValid(sheetName As String) As Boolean

'     Test the name passed as a string to see if it is a valid sheet name

IsSheetNameValid = False          ' Establish default
If Len(sheetName) = 0 Then Exit Function
If Len(sheetName) > 31 Then Exit Function
Dim InvalidCharacters As Variant
InvalidCharacters = Array("/", "\", "[", "]", "*", "?", ":")
Dim X As Integer
For X = LBound(InvalidCharacters) To UBound(InvalidCharacters)
    If InStr(sheetName, (InvalidCharacters(i))) > 0 Then Exit Function
Next
IsSheetNameValid = True
End Function