dumping data table into Excel file using C#

protected void ExportToPDF(object sender, EventArgs e)

{

    //Get the data from database into datatable

    string strQuery = "select empid, empname, city, postalcode" +

        " from employee";

    SqlCommand cmd = new SqlCommand(strQuery);

    DataTable dt = GetData(cmd);

    //Create a dummy GridView

    GridView GridView1 = new GridView();

    GridView1.AllowPaging = false;

    GridView1.DataSource = dt;

    GridView1.DataBind();

    Response.ContentType = "application/pdf";

    Response.AddHeader("content-disposition",

        "attachment;filename=abc.pdf");

    Response.Cache.SetCacheability(HttpCacheability.NoCache);

    StringWriter sw = new StringWriter();

    HtmlTextWriter hw = new HtmlTextWriter(sw);

    GridView1.RenderControl(hw);

    StringReader sr = new StringReader(sw.ToString());

    Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

    HTMLWorker htmlparser = new HTMLWorker(pdfDoc);

    PdfWriter.GetInstance(pdfDoc, Response.OutputStream);

    pdfDoc.Open();

    htmlparser.Parse(sr);

    pdfDoc.Close();

    Response.Write(pdfDoc);

    Response.End(); 

}