Hi,
Right click the sheet tab, view code and paste this in
Private Sub Worksheet_Change(ByVal Target As Range)
If Range("A1").Value = "lock" Then
ActiveSheet.Unprotect
Range("B1").Locked = True
ActiveSheet.Protect
Else
ActiveSheet.Unprotect
Range("B1").Locked = False
ActiveSheet.Protect
End If
End Sub
Mike