Function is_Integer(num)
' author : MicrobZ
' Date   :  04/03/2008
' desc   : check if given expression is integer

If (IsNumeric(num)) Then
    num = CStr(num)
    If InStr(1, num, ".")  Then
        is_Integer = False
        Exit Function
    End If
Else
is_Integer = False
Exit Function
End If

is_Integer = True

End Function