A connection attempt failed because the connected party did not properly respond after a period of time

Hello,

I got server error when downloading pdf file from my webpage in asp.net.

"A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond in asp.net."

Please tell me any solution.

 Code:

protected void btnPdf_Click(object sender, EventArgs e)
{
    imgphoto.Src = "http://localhost:51350/Project/imagesLogin/black.png";
    string imgurl = Convert.ToString(imgChart.ImageUrl);
    imgurl = imgurl.Replace("~", "");
    imgChart.ImageUrl = "D:/Project" + imgurl;
    Chart1.Visible = false;
    //lblOrganisationTitle.Font.Size = 14;
    lbltitle.Font.Size = 14;
    lblOrgname.Font.Size = 9;
    lblOrganisationname.Font.Size = 9;
    lblbatchName.Font.Size = 9;
    lblParticipantBatchname.Font.Size = 9;
    lblChapter.Font.Size = 9;
    lblChpaterName.Font.Size = 9;
    lbldesc.Font.Size = 9;
    lbldescription.Font.Size = 9;
    lblfooter.Font.Size = 8;
    Label1.Font.Size = 9;
    Label2.Font.Size = 9;
    Label3.Font.Size = 9;
    Label4.Font.Size = 9;
    MyImage.Visible = false;
    Image1.Visible = false;

    Response.ContentType = "application/pdf";
    Response.AddHeader("content-disposition", "attachment;filename=AudioViewReport.pdf");
    Response.Cache.SetCacheability(HttpCacheability.NoCache);
    StringWriter sw = new StringWriter();
    HtmlTextWriter hw = new HtmlTextWriter(sw);
    this.Page.RenderControl(hw);
    StringReader sr = new StringReader(sw.ToString());
    Document pdfDoc = new Document(PageSize.A4, 50f, 50f, 10f, 10f);

    HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
    PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
    pdfDoc.Open();

    Phrase phrase = null;
    PdfPCell cell = null;
    PdfPTable table = null;


    table = new PdfPTable(3);
    table.TotalWidth = 500f;
    table.LockedWidth = true;
    table.SetWidths(new float[] { 0.3f, 0.6f, 0.3f });

    iTextSharp.text.Image gifImage = iTextSharp.text.Image.GetInstance(Image1.ImageUrl);
    gifImage.ScalePercent(50f);
    // gifImage.Alignment = iTextSharp.text.Image.ALIGN_CENTER;      
    cell = new PdfPCell(gifImage);
    cell.BorderColor = BaseColor.WHITE;
    cell.HorizontalAlignment = Element.ALIGN_CENTER;
    table.AddCell(cell);

    phrase = new Phrase();
    phrase.Add(new Chunk("\n\n", FontFactory.GetFont("Arial", 16, Font.BOLD)));
    cell = PhraseCell(phrase, PdfPCell.ALIGN_LEFT);
    cell.VerticalAlignment = Element.ALIGN_TOP;
    table.AddCell(cell);

    cell = ImageCell("~/imagesLogin/darklogo_2.png", 50f, PdfPCell.ALIGN_CENTER);
    table.AddCell(cell);

    pdfDoc.Add(table);
    htmlparser.Parse(sr);
    pdfDoc.Close();
    Response.Write(pdfDoc);
    Response.End();
}

Thanks.