Lock cells vba

Got a sheet where order entry is entered in each row, column Z of the row, "approved" is entered. When approved is entered against the order I want the worksheet to lock that row and then protect the sheet.The next orders can then be entered and each time "approved is entered in that rows column z, the row should lock.

My code is
Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)

If Target.Column = "26" Then
    If UCase(Target.Value) = "Approved" Then
        ActiveSheet.Unprotect
        Target.EntireRow.Locked = True
        Target.Locked = True
        ActiveSheet.Protect
    End If
End If


End Sub

Bur I cant quite get it too work correctly