how to save image in folder using AsyncFileUpload in updatepanel on upload button click without postback

<asp:UpdatePanel ID="UpdatePanel1" runat="server" 
UpdateMode="Conditional" ChildrenAsTriggers="true">
 <contenttemplate>

 <asp:AsyncFileUpload ID="abcd1" runat="server" Height="25px" Width="242px" OnClientUploadComplete="uploadComplete"
  ThrobberID="imgLoader" OnClientUploadStarted="uploadStarted" 
OnClientUploadError="uploadError"  />

   <asp:Button ID="btnUpload" runat="server" Text="Upload" 
onclick="btnUpload_Click1" />
  </contenttemplate>
                                                                                      
                                                                                
  <triggers>                                                                           
    <asp:PostBackTrigger ControlID="btnUpload" />
   </triggers>
   
    </div>

<script type="text/javascript" language="javascript">

       function uploadError(sender, args) {
           document.getElementById('lblStatus').innerText = args.get_fileName(),
	             "<span style="color:red;">" + args.get_errorMessage() + "</span>";
       }

       function StartUpload(sender, args) {
           document.getElementById('lblStatus').innerText = 'Uploading Started.';
       }

       function UploadComplete(sender, args) {
           var filename = args.get_fileName();
           var contentType = args.get_contentType();
           var text = "Size of " + filename + " is " + args.get_length() + " bytes";
           if (contentType.length > 0) {
               text += " and content type is '" + contentType + "'.";
           }
           document.getElementById('lblStatus').innerText = text;
       }

   </script>

protected void btnUpload_Click1(object sender, EventArgs e)
{
try
{
    HttpFileCollection uploadFiles = Request.Files;
    for (int i = 0; i < uploadFiles.Count; i++)
    {
        HttpPostedFile uploadFile = uploadFiles[i];
        string fileName = Path.GetFileName(uploadFile.FileName);
        if (fileName.Trim().Length > 0)
        {
            uploadFile.SaveAs(Server.MapPath("~/Files/") + fileName);
               lblStatus.Text = "File Uploaded Successfully";
        }
    }
}
catch (Exception ex)
{
     lblStatus.Text = "Error in uploading file";
}

}