tabcycling is not working after datagridinsertin()

tabcycling is not working after datagridinsertin()

the processflow is following:

select guestdetails-->Employee details-->Details to grid-->Advance-->Discount.

tab cycling is moving nicely by default. but if we cycle the tab after gridinsertion it stay on hours textbox(data for datagridinsert)

question:

code : 

 private void txtnoofPer_KeyUp(object sender, KeyEventArgs e)
            {
            try
            {
                if (e.KeyCode == Keys.Enter)
                    {
                    ConfCheckinDetailsToGrid();
                   
                    }
             }

            

            catch (Exception ex) { }
        }

--------------------------
 public void ConfCheckinDetailsToGrid()  
        {
            if (txtTotalHours.Text != "0")
            {
                string roomID = Convert.ToString(cmbroomno.SelectedValue);
                object[,] ParamArray = new object[,] { { "@RoomID", roomID } };
                DataSet ds = new DataSet();
                ds = DB.ExecuteQuery_SP("SelectRoomDetailsForGridByID", ParamArray);
                if (ds.Tables.Count > 0)
                {
                    int row = 0;
                    row = dgvcheckin1.FirstFreeRow;
                    //dgvcheckin1.DataSource = null;
                    dgvcheckin1.Rows.Add();
                    row = dgvcheckin1.Rows.Count - 1;
                    dgvcheckin1.Rows[row].Cells["RoomNo"].Value = ds.Tables[0].Rows[0]["RoomNo"].ToString();

                    dgvcheckin1["RoomNo", row].Value = ds.Tables[0].Rows[0]["RoomNo"].ToString();
                    dgvcheckin1["RoomCategoryName", row].Value = ds.Tables[0].Rows[0]["RoomCategoryName"].ToString();
                    dgvcheckin1["RoomCapacity", row].Value = ds.Tables[0].Rows[0]["RoomCapacity"].ToString();
                    dgvcheckin1["NoofPerson", row].Value = txtTotalHours.Text;
                    dgvcheckin1["Hours", row].Value = txtTotalHours.Text;
                    dgvcheckin1["InTime", row].Value = dtpchkintime.Text;
                    dgvcheckin1["CheckInDate", row].Value = dtpcheckin.Text;
                    dgvcheckin1["Rents", row].Value = ds.Tables[0].Rows[0]["PerdayRent"].ToString();
                    dgvcheckin1["TaxAmount", row].Value = ds.Tables[0].Rows[0]["TaxAmount"].ToString();
                    dgvcheckin1["CheckOutday", row].Value = dtpcheckOutdate.Text;
                    dgvcheckin1["CheckOutTime", row].Value = dtpouttime.Text;
                    dgvcheckin1["Roomid", row].Value = cmbroomno.SelectedValue;
                    if (Convert.ToInt32(txtTotalHours.Text) > 1)
                    {
                        double NetTotal = ((Convert.ToDouble(ds.Tables[0].Rows[0]["PerdayRent"]) + Convert.ToDouble(ds.Tables[0].Rows[0]["TaxAmount"])) + ((PolosysHMS.General.Classes.Settings.InventorySettings.ExtraHoursCost) * (Convert.ToDouble(txtTotalHours.Text) - 1)));
                        dgvcheckin1.Rows[row].Cells["NetTotal"].Value = NetTotal.ToString();
                    }
                    //dgvcheckin["RoomId",row].Value = ds.Tables[0].Rows[0]["RoomID"].ToString();


                    RoomCap = Convert.ToInt32(dgvcheckin1.Rows[row].Cells["RoomCapacity"].Value);


                    rent = Convert.ToDouble(dgvcheckin1.Rows[row].Cells["Rents"].Value.ToString());
                    tax = Convert.ToDouble(dgvcheckin1.Rows[row].Cells["TaxAmount"].Value.ToString());



                    No_Of_Hours = Convert.ToInt32(dgvcheckin1.Rows[row].Cells["Hours"].Value);
                    //if (txtnoofPer.Text == "")
                    //{
                    //    txtnoofPer.Text = "0";
                    //}
                    No_of_Person = Convert.ToInt32(dgvcheckin1.Rows[row].Cells["NoofPerson"].Value);

                    //if (No_of_Person > RoomCap)
                    //{
                    //    Ext_Person = No_of_Person - RoomCap;
                    //    add_amt_forRoom = Ext_Person * 50;
                    //    txttotal.Text = Convert.ToString((rent + tax + add_amt_forRoom) * No_Of_days);
                    //    total += Convert.ToDouble(txttotal.Text);
                    //    txttotal.Text = Convert.ToString(total);
                    //    txtbalance.Text = Convert.ToString(total);
                    //}
                    //else
                    //{
                    double NetTotalCal = Convert.ToDouble(dgvcheckin1.Rows[row].Cells["NetTotal"].Value);


                    double totatl = +NetTotalCal;
                    txttotal.Text = totatl.ToString();

                    //txttotal.Text = Convert.ToString((rent + tax) * No_Of_Hours);
                    // total += Convert.ToDouble(txttotal.Text);
                    // txttotal.Text = Convert.ToString(total);
                    txtbalance.Text = Convert.ToString(totatl);
                    txtBillingAmount.Text = Convert.ToString(totatl);
                    Bal(txtbalance, txttotal, txtadvance, txtDiscount);

                }
            }
            //int Roomno_Bookingprocess = Convert.ToInt32(cmbroomno);
            //objGeneralclass.UpdateOnBookingProcess(Convert.ToInt32(cmbroomno.SelectedValue), true);
            ClearInputGridField();
        }
-------------------------------------------


	tested solution : 

	1.	I checked any focus on hourstextbox. 
	2.	test with out updateBookingprocess()function
	3.	test with out ClearInputGridfield()