runtime error 7768 in order to change..blah (1 Viewer)

ok. here's the deal

Private Sub cmdsave_Click()
On Error GoTo err_handler

Dim lnglaptime As Long

lnglaptime = Me.txtLapNumber.Value

Me.Dirty = True
Me.lstAll.Requery

Me.lstAll.Value = lnglaptime

exitpoint:
Exit Sub
err_handler:
MsgBox Err.Description, , "Error in cmdSave"
Resume exitpoint
Resume
End Sub

I don't no whats happening, the error is apprently in the "me.dirty = true" but i dont know. Help?

Why are you attempting to set the Dirty property True?