Export Gridview to Excel

protected void Page_Load(object sender, EventArgs e)
{
    con.Open();
    if (!IsPostBack)
    {
       BindData();
    }
    con.Close();
        
}

private void BindData()
{
    string sql = "select * from Student";
    SqlDataAdapter adpter = new SqlDataAdapter(sql, con);
    DataSet ds = new DataSet();
    adpter.Fill(ds);

    MyGrid.DataSource = ds;
    MyGrid.DataBind();
}

protected void bnt_Click(object sender, EventArgs e)
{

    Response.Clear();
    Response.AddHeader("content-disposition",   "attachment;filename=FileName.xls");
    Response.Charset = "";
 
    Response.ContentType = "application/vnd.ms-excel";
    Response.Charset = "";
    this.EnableViewState = false;
    System.IO.StringWriter SW = new System.IO.StringWriter();
    System.Web.UI.HtmlTextWriter HTW = new HtmlTextWriter(SW);
   
    MyGrid.RenderControl(HTW);
    Response.Write(SW.ToString());
    Response.End();
}

public override void VerifyRenderingInServerForm(Control control)
{
        /* Confirms that an HtmlForm control is rendered for the specified ASP.NET
           server control at run time. */
}