Can anyone shed some light on why this code won't work for me? Worksheet Change doesn't seem to fire when P3 becomes "13" or "43". It seems to work with Workbook Sheet Selection Change, but then the msgbox keeps popping up every time I click a cell/button after 13 or 43 is within the cell, I only wish for the msgbox to appear once. 

Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = True

If Not Intersect(Target, Range("P3")) Is Nothing Then

    Select Case Target.Value
    
        Case Is = "13"
        
            MsgBox "Message Box"
            
        Case Is = "43"
        
            MsgBox "Another Message Box"
            
        Case Else
        
            Exit Sub
            
    End Select
    
End If
End Sub
Please note I have also tried Worksheet Calculate and this doesn't do anything either. I'm not getting any error messages or debugs.