BindingSource & DataGrid on MouseClick

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace My_WindowsForm_Example
{
    public partial class Form1 : Form
    {
        SqlConnection conn = new SqlConnection("server=PC;integrated security=true;database=northwind");
        SqlDataAdapter da = new SqlDataAdapter();
        DataSet ds = new DataSet();
        BindingSource tblNamesBS = new BindingSource();


        public Form1()
        {
            InitializeComponent();
        }

        private void btnAddRecord_Click(object sender, EventArgs e)
        {
            da.InsertCommand = new SqlCommand("insert into employees (LastName,FirstName,Title,Country,City,BirthDate) values(@LastName,@FirstName,@Title,@COuntry,@City,@BirthDate)", conn);

            
            da.InsertCommand.Parameters.Add("@LastName", SqlDbType.NVarChar).Value = txtLastName.Text;
            da.InsertCommand.Parameters.Add("@FirstName", SqlDbType.NVarChar).Value = txtFirstName.Text;
            da.InsertCommand.Parameters.Add("@Title", SqlDbType.NVarChar).Value = txtTitle.Text;
            da.InsertCommand.Parameters.Add("@Country", SqlDbType.NVarChar).Value = txtCountry .Text ;
            da.InsertCommand.Parameters.Add("@City", SqlDbType.NVarChar).Value = txtCity .Text ;
            da.InsertCommand.Parameters.Add("@BirthDate", SqlDbType.DateTime).Value =Convert .ToDateTime ( txtBirthDate.Text);

            conn.Open();
            da.InsertCommand.ExecuteNonQuery();
            conn.Close();
        }

        private void btnDisplay_Click(object sender, EventArgs e)
        {
            da.SelectCommand = new SqlCommand("select EmployeeID,FirstName,LastName,Title,Country,City,BirthDate from Employees",conn );

            ds.Clear();

            da.Fill(ds,"Employees");

            dg.DataSource = ds.Tables["Employees"];

            tblNamesBS .DataSource =ds.Tables ["Employees"];

            txtFirstName.DataBindings.Clear();
            txtFirstName.DataBindings.Add(new Binding("Text", tblNamesBS, "FirstName"));

            txtLastName.DataBindings.Clear();
            txtLastName.DataBindings.Add(new Binding("Text", tblNamesBS, "LastName"));

            txtTitle.DataBindings.Clear();
            txtTitle.DataBindings.Add(new Binding("Text", tblNamesBS, "Title"));

            txtCountry.DataBindings.Clear();
            txtCountry.DataBindings.Add(new Binding("Text", tblNamesBS, "Country"));

            txtCity.DataBindings.Clear();
            txtCity.DataBindings.Add(new Binding("Text", tblNamesBS, "City"));

            txtBirthDate.DataBindings.Clear();
            txtBirthDate.DataBindings.Add(new Binding("Text", tblNamesBS, "BirthDate"));

            
            Records();
            
        }

        private void btnFirst_Click(object sender, EventArgs e)
        {
            tblNamesBS.MoveFirst();
            dgUpdate();
            Records();
        }

        private void btnPrevious_Click(object sender, EventArgs e)
        {
            tblNamesBS.MovePrevious();
            dgUpdate();
            Records();
        }

        private void btnNext_Click(object sender, EventArgs e)
        {
            tblNamesBS.MoveNext();
            dgUpdate();
            Records();
        }

        private void btnLast_Click(object sender, EventArgs e)
        {
            tblNamesBS.MoveLast();
            dgUpdate();
            Records();
        }
        private void dgUpdate()
        {
            dg.ClearSelection();
            dg.Rows[tblNamesBS.Position].Selected = true;
            
            Records();
        }
        private void Records()
        {
            label7.Text = "Record " + (tblNamesBS.Position + 1) + " of " + tblNamesBS.Count;
        }

        private void btnUpdate_Click(object sender, EventArgs e)
        {
            da.UpdateCommand = new SqlCommand("Update Employees set lastname=@lastname,firstname=@firstname,title=@title,country=@country,city=@city,birthdate=@birthdate where EmployeeID=@ID",conn );

            da.UpdateCommand.Parameters.Add("@lastname", SqlDbType.NVarChar).Value = txtLastName.Text;
            da.UpdateCommand.Parameters.Add("@firstname", SqlDbType.NVarChar).Value = txtFirstName.Text;
            da.UpdateCommand.Parameters.Add("@title", SqlDbType.NVarChar).Value = txtTitle.Text;
            da.UpdateCommand.Parameters.Add("@country", SqlDbType.NVarChar).Value = txtCountry.Text;
            da.UpdateCommand.Parameters.Add("@city", SqlDbType.NVarChar).Value = txtCity.Text;
            da.UpdateCommand.Parameters.Add("@birthdate", SqlDbType.DateTime ).Value = Convert .ToDateTime (txtBirthDate.Text);
            da.UpdateCommand.Parameters.Add("@ID", SqlDbType.Int).Value = ds.Tables["Employees"].Rows[tblNamesBS.Position][0];

            conn.Open();
            da.UpdateCommand.ExecuteNonQuery();
            conn.Close();
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            DialogResult dr = new DialogResult();

            dr=MessageBox.Show("Are You Sure?\nThere is no undo once data is deleted", "Confirm Deletion", MessageBoxButtons.YesNo);

            if (dr == DialogResult.Yes)
            {

                da.DeleteCommand = new SqlCommand("delete from  Employees  where EmployeeID=@ID and FirstName=@FirstName", conn);
                da.DeleteCommand.Parameters.Add("@ID", SqlDbType.Int).Value = ds.Tables["Employees"].Rows[tblNamesBS.Position][0];
                da.DeleteCommand.Parameters.Add("@FirstName", SqlDbType.VarChar).Value = txtFirstName.Text;

                conn.Open();
                da.DeleteCommand.ExecuteNonQuery();
                conn.Close();
            }
            else
            {
                MessageBox.Show("Deletion canceled");
            }
        }

        private void btnSearch_Click(object sender, EventArgs e)
        {
            da.SelectCommand = new SqlCommand("select firstname,lastname,title,country,city,birthdate from employees where lastname=@lastname and firstname=@firstname ",conn);

            
            da.SelectCommand.Parameters.Add("@lastname", SqlDbType.NVarChar).Value = txtLastName.Text;
            da.SelectCommand.Parameters.Add("@firstname", SqlDbType.NVarChar).Value = txtFirstName.Text;
           

            conn.Open();
            da.SelectCommand.ExecuteNonQuery();
            ds.Clear();
            da.Fill(ds, "Employees");
            dg.DataSource = ds.Tables["Employees"];
            conn.Close();
            
        }

        private void dg_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
        {
            dg.Rows[tblNamesBS.Position].Selected = true;//Ovo nece radit kako treba
        }

     
    }
}