How do I upload several files with ajaxToolkit:AsyncFileUpload

<ajaxToolkit:AsyncFileUpload OnClientUploadError="uploadError" OnClientUploadComplete="uploadComplete" runat="server"
                ID="AsyncFileUpload1" UploaderStyle="Traditional" CompleteBackColor="White" UploadingBackColor="#CCFFFF"
                ThrobberID="imgLoader" OnUploadedComplete="FileUploadComplete" />

protected void FileUploadComplete(object sender, EventArgs e)
        {
            
            string filename = System.IO.Path.GetFileName(AsyncFileUpload1.FileName);
            AsyncFileUpload1.SaveAs(Server.MapPath("Uploads/") + filename);
            byte[] file = new byte[AsyncFileUpload1.PostedFile.InputStream.Length];
            file = ReadFile(AsyncFileUpload1.PostedFile.InputStream);
            Session["File"] = file;

        }