Ionic.Zip - Download Zip Multiple Files for Stream

Response.Clear();
Response.BufferOutput = false;  // for large files
Response.ContentType = "application/zip";
Response.AddHeader("content-disposition", "filename=Report.zip");

using (ZipFile zip = new ZipFile())
{
    for (int idx = 0; idx <= FileList.Rows.Count - 1; idx++)
   {
        CheckBox cb = (CheckBox)FileList.Rows[idx].FindControl("RowLevelCheckBox");
        if (cb.Checked)
       {
            zip.AddFile(@url, "");
        }              
    }
    zip.Save(Response.OutputStream);
    Response.Close();
}