How to save the pdf file in any of the public folder in client machine without showing the download diagolue box

protected void btnPrint_Click(object sender, EventArgs e) 
    {
                   

            Warning[] warnings;
            string[] streamids;
            string mimeType;
            string encoding;
            string extension;
            string deviceInfo = string.Empty;

            deviceInfo = "<DeviceInfo><SimplePageHeaders>True</SimplePageHeaders></DeviceInfo>";

            byte[] data = ReportViewer1.ServerReport.Render(
               "PDF", null, out mimeType, out encoding, out extension,
               out streamids, out warnings);

            //Identify the Client Machine Desktop folder Path
            string ClientDesktopPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "");            

            //DirPath = Server.MapPath(@"" + "~/Temp") + @"\" + "TempReportFiles";//Server.MapPath("~") returns the physical path to the root of the application
            PDFFileName = "OutPutTmpRpt" + SessionHandler.UserID.Trim() + ".pdf"; //Set the File name here
           
            using (FileStream fs = new FileStream(ClientDesktopPath + @"\" + PDFFileName.Trim(), FileMode.Create)) 
            {
                fs.Write(data, 0, data.Length);
                fs.Close();
                fs.Dispose();
            }
}