Visual Basic

Public Function Get_Data_Straight(ByVal strNumkey As String) As DataSet
      Dim con As SqlConnection
      Dim strSQl As String = "SELECT Primary_ID, Boundary_area, Attrib_Code, Lis_Key, Func_Key, Actual_Extent, Improved_Value, Site_Value, Purchase_price, Purchase_date, prop_id, confidence_score, fin_ls_prediction, new_lis_key, new_func_key, Tshwane_Prediction, matchflag, source, flagtype, Locked FROM Property_mass WHERE (SUBSTRING(Lis_Key, 1, 4) = @Lis_key) AND (Locked IS NULL)"
      Dim constr As String = "user id=sde;Password=XXXXX;Server=XXXXXXXXX;persist security info=False;initial catalog=Tshwane_Valuations_Train"
      Dim cmd As SqlCommand
      Dim cmb As SqlCommandBuilder
      Dim da As SqlDataAdapter
      Dim ds As DataSet
      Try
          ds = New DataSet
          con = New SqlConnection(constr)
          con.Open()
          'Inituializing the Connection Object
          cmd = New SqlCommand(strSQl)
          'Telling the connection object where is the Database
          cmd.Connection = con
          'Initializing the adapter
          da = New SqlDataAdapter
          da.SelectCommand.Parameters.Add("@Lis_key", strNumkey)
          ' da.SelectCommand.Parameters.Add(New SqlParameter("@Lis_Key", strNumkey))

          'we tell the adapter which object we are using
          da.SelectCommand = cmd
          da.Fill(ds, "Property_Mass")

      Catch ex As SqlClient.SqlException

          MsgBox(ex.Message)

      End Try
      Return ds

  End Function

An unhandled exception of type 'System.NullReferenceException' occurred in propdal.dll

Additional information: Object reference not set to an instance of an object.

da.SelectCommand.Parameters.Add("@Lis_key", strNumkey)