Поиск строки в DataGridView 2

[tehadm]

    using System;
    using System.Data;
    using System.Windows.Forms;
    using System.Data.SqlClient;
     
    namespace SearchRecord
    {
        public partial class frmSearch : Form
        {
            //Connection String
            string cs = "Data Source=.;Initial Catalog=Sample;Integrated Security=true;";
            SqlConnection con;
            SqlDataAdapter adapt;
            DataTable dt;
            public frmSearch()
            {
                InitializeComponent();
            }
            //frmSearch Load Event
            private void frmSearch_Load(object sender, EventArgs e)
            {
                con = new SqlConnection(cs);
                con.Open();
                adapt = new SqlDataAdapter("select * from tbl_Employee",con);
                dt = new DataTable();
                adapt.Fill(dt);
                dataGridView1.DataSource = dt;
                con.Close();
            }
            //txt_SearchName TextChanged Event
            private void txt_SearchName_TextChanged(object sender, EventArgs e)
            {
                con = new SqlConnection(cs);
                con.Open();
                adapt = new SqlDataAdapter("select * from tbl_Employee where FirstName like '"+txt_SearchName.Text+"%'", con);
                dt = new DataTable();
                adapt.Fill(dt);
                dataGridView1.DataSource = dt;
                con.Close();
            }
        }
    }