locking a cell after data imput

[simpson]

I found this code and was wondering if someone could help me get it to work. and also answer a few questions about its capabilities.

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Target, Range("b1:b10")) Is Nothing Then

    If Target.Locked = False Then
    ActiveSheet.Unprotect "xxx"
    Target.Locked = True
    ActiveSheet.Protect "xxx"
    End If
    End If

End Sub

I need it to be; if sheet 2 A1= sheet1 A1 then lock b1.