ช่วยดูให้หน่อยครับว่าผิดตรงไหนครับ เกี่ยวกับ Datediff ครับ

 Private Sub datagrid_bill_CellClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles datagrid_bill.CellClick
        Dim i As Integer = datagrid_bill.CurrentRow.Index
        Dim key As String = datagrid_bill.Item(5, i).Value
        connect_open()
        sql = "select claimout_proid, claimout_promodel, claimout_proname, claimout_procolor, claimout_prosn, claimout_probad, claimout_eqment, claimout_snout, claimout_innote, claimout_idfull from claimout where claimout_idfull='" & key & "'"
        DA = New SqlDataAdapter(sql, cn)
        DS = New DataSet
        DA.Fill(DS, "table")

        datagrid_detels.DataSource = DS.Tables("table")
        txt_custuid.Text = datagrid_bill.Item(1, i).Value
        txt_custuname.Text = datagrid_bill.Item(2, i).Value
        txt_custuaddress.Text = datagrid_bill.Item(3, i).Value
        txt_custutransp.Text = datagrid_bill.Item(4, i).Value
        txt_billid.Text = datagrid_bill.Item(5, i).Value
        txt_datein.Text = datagrid_bill.Item(6, i).Value
        txt_dateout.Text = datagrid_bill.Item(7, i).Value
        txt_billtotals.Text = datagrid_bill.Item(8, i).Value
        chang_detel_column()
        lbl_counts.Text = datagrid_detels.Rows.Count

        lbl_dateto.Text = DateDiff(DateInterval.Hour, CDate("'" & txt_dateout.Text & "'"), CDate("'" & Date.Today & "'"))

    End Sub