protected void btnExport_Click(object sender, EventArgs e)
{




    Response.Clear();
    Response.Buffer = true;
                   Response.ContentType="application/vnd.openxmlformatsofficedocument.wordprocessingml.documet";
    Response.AddHeader("Content-Disposition", "attachment; filename=WORK_ORDER.doc");
    Response.ContentEncoding = System.Text.Encoding.UTF8;
    Response.Charset = "";
    EnableViewState = false;
    System.IO.StringWriter writer = new System.IO.StringWriter();
    System.Web.UI.HtmlTextWriter html = new System.Web.UI.HtmlTextWriter(writer);
    xx.RenderControl(html);
    Response.Write(writer);
    Response.End();