Widget with link to remote document

Hi, 

I'm tring to create simple widget with link to remote document:

<%@ Control Language="C#" AutoEventWireup="true" %>

<%@ Import Namespace="System.Net"%>

<%@ Import Namespace="System.IO"%>

<script runat="server" language="C#">

        protected void LinkButton1_Click(object sender, EventArgs e)

        {

                    string username = "UserName";

                    string userpassword = "Pass";

                    string domain = "Domain";

                    NetworkCredential networkCredential = new NetworkCredential(username, userpassword, domain);

                    WebClient webClient = new WebClient();

                    webClient.Credentials = networkCredential;

                    Byte[] buffer = webClient.DownloadData("http://localhost/Docs/Documents/1.jpg");

                    MemoryStream memoryStream = new MemoryStream(buffer);

                    Response.Clear();

                    Response.ContentType = "application/octet-stream";

                    Response.AddHeader("Content-Disposition", "attachment; filename=" + "1.jpg");

                    memoryStream.WriteTo(Response.OutputStream);

                    Response.End();

        }

</script>

<asp:LinkButton ID="LinkButton1" runat="server" onclick="LinkButton1_Click">LinkButton</asp:LinkButton>

But filesize is incorrect (remote filesize: 22kb ,when downloaded from widget: 40kb). This problem didn't depend on file.

What's wrong?

Thanks