Please help, I have macro that runs and selects another sheet in my workbook. I can't get the bit of VB code I have set up to work on the newly selected sheet.

What could be stopping it? Any idea? I have copied a bit of the VB code below.

Private Sub Worksheet_Change(ByVal Target As Excel.Range)
If Target.Address = "$M$22" And Target.Value = "n" Then
MsgBox ("Now enter a valid reason")
ActiveCell.Offset(-1, 3).Select
End If

End Sub