What Wrong with this code,It doesn't help to search record in Gridview?
<p>I am creating one gridview in asp.net ,now i want to search the record from the gridview ,but im not getting what actually do,please help me!  </p>

<pre><code>   private DataTable GetRecords()
            {
                SqlConnection con = new SqlConnection(constring);
                con.Open();
                SqlCommand cmd = new SqlCommand("Select * from supplier", con);
                SqlDataAdapter da = new SqlDataAdapter();
                da.SelectCommand = cmd;
                DataSet ds = new DataSet();
                da.Fill(ds);
                return ds.Tables[0];

            }
            protected void btn_search_Click(object sender, EventArgs e)
            {
                string searchtext = TextBox1.Text;
                SearchText(searchtext);
            }

            private void SearchText(string search_text)
            {
                DataTable dt = GetRecords();
                DataView dv = new DataView(dt);
                string SearchExpression = null;
                if (!String.IsNullOrEmpty(search_text))
                {
                    SearchExpression = string.Format("{0} '%{1}%'", GridView1.SortExpression, search_text);

                }
                dv.RowFilter = "part_no like " + SearchExpression;
                GridView1.DataSource = dv;
                GridView1.DataBind();
            }
</code></pre>
