Problems in Uploading and Downloading files in SQL Server'08 database

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C#

ASP.NET

SQL-Server

Hi Everyone,

I'm working on a messages module of a project in which registered users can send messages to each other. Everything works fine in case of uploading attachments and sending message but in INBOX module, there is a problem in downloading attachments. Below is the code which I'm using for uploading and downloading attachments.

Uploading and Sending Message:

string s = txtids.Text;
string[] eids = s.Split(',');

if (FileUpload1.HasFile)
            {
                //SqlDataSource1.Insert();
                string fileName = FileUpload1.PostedFile.FileName;
                string fileType = FileUpload1.PostedFile.ContentType;
                int contentLength = Convert.ToInt32(FileUpload1.PostedFile.InputStream.Length);
                byte[] bytContent = new byte[contentLength];
                int status = FileUpload1.PostedFile.InputStream.Read(bytContent, 0, contentLength);
                
                foreach (string eid in eids)
                {
                        cmd = new SqlCommand("insert into messages(sender_ID, receiver_ID, m_subject, m_content, file_name, file_extension, file_content) values ('" + Session["uid"] + "','" + eid.ToString().Trim() + "','" + txtsub.Text.Trim() + "','" + txtbody.Text.Trim() + "', @FileName, @Extension, @Content)", con);
                        SqlParameter prmFileName = new SqlParameter("@FileName", SqlDbType.NVarChar, 1000);
                        prmFileName.Value = fileName;
                        cmd.Parameters.Add(prmFileName);
                        SqlParameter prmContentType = new SqlParameter("@Extension", SqlDbType.NVarChar, 300);
                        prmContentType.Value = fileType;
                        cmd.Parameters.Add(prmContentType);
                        SqlParameter prmbytContent = new SqlParameter("@Content", SqlDbType.VarBinary);
                        prmbytContent.Value = bytContent;
                        cmd.Parameters.Add(prmbytContent);
                        cmd.ExecuteNonQuery();
                }
                Response.Redirect("compose_message.aspx");
            }
            else
            {
                String str = "N/A";
                byte[] arr = System.Text.Encoding.ASCII.GetBytes(str); 
                foreach (string eid in eids)
                {
                    cmd = new SqlCommand("insert into messages(sender_ID, receiver_ID, m_subject, m_content, file_name, file_extension, file_content) values ('" + Session["uid"] + "','" + eid.ToString().Trim() + "','" + txtsub.Text.Trim() + "','" + txtbody.Text.Trim() + "',@FileName, @Extension, @Content)", con);
                    SqlParameter prmFileName = new SqlParameter("@FileName", SqlDbType.NVarChar, 1000);
                    prmFileName.Value = str;
                    cmd.Parameters.Add(prmFileName);
                    SqlParameter prmContentType = new SqlParameter("@Extension", SqlDbType.NVarChar, 300);
                    prmContentType.Value = str;
                    cmd.Parameters.Add(prmContentType);
                    SqlParameter prmbytContent = new SqlParameter("@Content", SqlDbType.VarBinary);
                    prmbytContent.Value = arr;
                    cmd.Parameters.Add(prmbytContent);
                    cmd.ExecuteNonQuery();
                }
            }

Source Code for Downloading Files:

protected void LinkButton1_Click(object sender, EventArgs e)
{
    SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["E-PM"].ConnectionString);
    SqlCommand cmd = new SqlCommand("Select file_extension, file_content from messages where m_ID = '" + Session["mid"] + "'", conn);
    conn.Open();

    SqlDataReader Reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
    Reader.Read();
    Response.Clear();

    Response.ContentType = Reader["file_extension"].ToString();
    byte[] reportFile = (byte[])Reader["file_content"];

    Response.Buffer = true;
    Response.Charset = "";
    Response.Cache.SetCacheability(HttpCacheability.NoCache);
    Response.BinaryWrite(reportFile);
    Response.Flush();
    Response.End();
    conn.Close();
}

What I want is when user click on Link Button (Download), a file-save dialog box should open and ask user for saving location of file.

Any kind of help is very much appreciated.

Thank You