这段下载代码那出错了，高手帮忙看下。谢谢

 string sID = GridView1.DataKeys[GridView1.SelectedIndex].Value.ToString();
        if (sID.Length < 1)
            sID = "-1";
        byte[] FileData = null;
        string fileName = "";
        string type = "";        string strSQL = "select * from 文档 where id = " + sID;
        sqlconn = new SqlConnection(conn);
        sqlconn.Open();
        SqlCommand cmd = new SqlCommand(strSQL, sqlconn);
        SqlDataReader reader = cmd.ExecuteReader();
        if (reader.Read())
        {
            fileName = reader["文档名称"].ToString();
            type = reader["文档类型"].ToString();
            FileData = (byte[])reader["文档数据"];
            if (FileData != null)
            {
            Response.Clear();
            Response.Buffer = false;
            Response.ClearContent();
            Response.ClearHeaders();
            Response.Charset = "GB2312";
            Response.ContentType = "application/octet-stream"; // 设置输出流的Http MIME类型                 //Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            Response.BinaryWrite(FileData);// 写入输入流
            Response.Flush(); // 向客户端发送数据流            
            Response.Close();
            Response.End();