Cannot show data to gridview from oracle database in windows application pls help

#region course selected index
        private void CB_Course_SelectedIndexChanged(object sender, EventArgs e)
        {
            coursewisereport();
        }
        #endregion

#region grid coursewisereport
        private void coursewisereport()
        {
            try
            {
                objdatabaseclass = new DataBaseClass();
                objstudentlistclass = new property_function_class.StudentListClass();
                objstudentlistclass.COURS = CB_Course.Text.Trim();
                dataset = objstudentlistclass.Getcoursewisereport();
                dbBindSource.DataSource = dataset;
                DbGrid.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCells);
                DbGrid.DataSource = dbBindSource;
            }
            catch
            {
                MessageBox.Show("selected data not in db");
            }
        }
        #endregion

#region getcoursewisereport function
        public DataSet Getcoursewisereport()
        {
            DataBaseClass objdatabaseclass = new DataBaseClass();
            dataset = new DataSet();
            dataset = objdatabaseclass.GetDataset(string.Format("select studentid,name,nameofgud,location,mobile from registration where course='" + course + "'"));
            return dataset;
        }
        #endregion

public DataSet GetDataset(string ProcedureName)
        {
            try
            {
                Objcommand = new OracleCommand(ProcedureName, Objconnection);
                Objcommand.CommandType = CommandType.Text;

                // Handle the parameters

                Objadapter = new OracleDataAdapter(Objcommand);
                objcommandbuilder = new OracleCommandBuilder(Objadapter);
                Objdataset = new DataSet();
                Objdataset.Locale = System.Globalization.CultureInfo.InvariantCulture;
                Objadapter.Fill(Objdataset);
            }

            catch (Exception Objerrormessage)
            {
                throw Objerrormessage;
            }
            finally
            {
                //release all resource of connection object
                Objconnection.Dispose();

            }
            return Objdataset;

        }