Add new data in database using C#

public void beginTrans()
        {
            try
            {
                if (dbTran == null)
                {
                    if (dbConn.State == 0) { createConn(); }
                    dbTran = dbConn.BeginTransaction();
                    dbCommand.Transaction = dbTran;
                    dbAdapter.SelectCommand.Transaction = dbTran;
                    dbAdapter.InsertCommand.Transaction = dbTran;
                    dbAdapter.UpdateCommand.Transaction = dbTran;
                    dbAdapter.DeleteCommand.Transaction = dbTran;
                }
            }
            catch (Exception exc) { throw exc; }
        }

        public void commitTrans()
        {
            try
            {
                if (dbTran != null)
                {
                    dbTran.Commit();
                    dbTran = null;
                }
            }
            catch (Exception exc) { throw exc; }
        }

        public void rollBackTrans()
        {
            try
            {
                if (dbTran != null)
                {
                    dbTran.Rollback();
                    dbTran = null;
                }
            }
            catch (Exception exc)
            {
                throw exc;
            }
        }

public DataSet insertQuery(DataSet ds, Hashtable ht)
        {
            try
            {
                dTable = ds.Tables[0];
                dRow = dTable.NewRow();
                object value;
                foreach (string ha in ht.Keys)
                {
                    value = ht[ha];
                    dRow[ha] = value;
                }
                dTable.Rows.Add(dRow);
                return ds;
            }
            catch (Exception exc) { throw exc; }
        }

public override void insert_lavlah(Hashtable hash)
        {
            try
            {
                dAccess.beginTrans();
                dSet.Clear();
                getDSet = dAccess.insertQuery(dSet, hash);
                dAccess.commitTrans();
            }
            catch (Exception exc)
            {
                dAccess.rollBackTrans();
                throw exc;
            }
        }

private void btnOk_zereg_Click(object sender, EventArgs e)
        {
            // bagshiin zeregt ogogdol nemeh
            //zereg.save_lavlah();
            Hashtable hTab = new Hashtable();
            hTab.Add("zereg_code", Convert.ToInt32(txtID_addZereg.Text));
            hTab.Add("zereg_ner", txtName_addZereg.Text);
            zereg.insert_lavlah(hTab);
            txtID_addZereg.Clear();
            txtName_addZereg.Clear();
            gbox_addZereg.Visible = false;

            //zereg.save_lavlah();
        }