ASP.NET

string strQuery = "select Pic from MEN where id='1'";
SqlCommand cmd = new SqlCommand(strQuery);
Convert.ToInt32(Request.QueryString["ImageID"]);
cmd.Parameters.Add("1", SqlDbType.Int).Value = Convert.ToInt32(Request.QueryString["ImageID"]);
DataTable dt = GetData(cmd);

if (dt != null)
{
   Byte[] bytes = (Byte[])dt.Rows[0]["Pic"];
   Response.Buffer = true;
   Response.Charset = "";
   Response.Cache.SetCacheability(HttpCacheability.NoCache);
   //Response.ContentType = dt.Rows[0]["ContentType"].ToString();
   Response.ContentType = dt.Rows[0]["PIC"].ToString();
   Response.AddHeader("content-disposition", "attachment;filename=" + dt.Rows[0]["PIC"].ToString());
   Response.BinaryWrite(bytes);
   Response.Flush();
   Response.End();
}
and this:

private DataTable GetData(SqlCommand cmd)
{
   DataTable dt = new DataTable();
   String strConnString = "server=" + Server + ";database=" + DataBase + ";UID=" + UID + ";password=" + PASS + ";";

   SqlConnection con = new SqlConnection(strConnString);
   SqlDataAdapter sda = new SqlDataAdapter();
   cmd.CommandType = CommandType.Text;
   cmd.Connection = con;

   try
   {
      con.Open();
      sda.SelectCommand = cmd;
      sda.Fill(dt);
      return dt;
   }
   catch
   {
      return null;
   }
   finally
   {
      con.Close();
      sda.Dispose();
      con.Dispose();
   }
}

<asp:image ID="Image2" runat="server" ImageUrl ="PhoneBook.aspx?ImageID=1"/>

DataTable dtChallanDtl = new DataTable();
        dtChallanDtl = (DataTable)ViewState["ChallanDtl"];
        int i = 0;
        int ChallanRcvd = 1;
        foreach (GridViewRow r in gvChallanDtl.Rows)
        {
            CheckBox chk = (CheckBox)r.FindControl("CheckSelect");
            TextBox txt = (TextBox)r.FindControl("txtRecvQty");
            if (chk.Checked == true)
            {
                dtChallanDtl.Rows[i]["Received"] = 1;
            }
            else
            {
                ChallanRcvd = 2;
            }
            if (dtChallanDtl.Rows[i]["RecvQty"].ToString() != txt.Text)
            {
                dtChallanDtl.Rows[i]["RecvQty"] = txt.Text;
                dtChallanDtl.Rows[i]["Received"] = 2;
                ChallanRcvd = 2;
            }
            i++;
        }