Worksheet SelectionChange Error - Target.Address - if statement

[anish.ms]

Hi,

Could somebody please help me with the below
why the below if statement is not working?

If Target.Address <> "$D$7" Or Target.Address <> "$M$5" Or Target.Address <> "$M$6" Then Exit Sub
          ShowCalendar
End Sub

Do I really need the following select statement?

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    Select Case Target.Address
        Case "$D$7"
            ShowCalendar
        Case "$M$5"
            ShowCalendar
        Case "$M$6"
            ShowCalendar
        Case Else
            Exit Sub
    End Select
End Sub