Pass additional data to jQuery Uploadify Plugin in ASP.Net

I can build a Gmail style file uploader using JQuery and Uploadify plugin for JQuery in ASP.Net with the help of this article

 My question is how can i pass the value(product id ) from label so i can insert the product id  in image table

<script type = "text/javascript">
$(window).load(
    function() {
    $("#<%=FileUpload1.ClientID %>").fileUpload({
        'uploader': 'scripts/uploader.swf',
        'cancelImg': 'images/cancel.png',
        'buttonText': 'Browse Files',
        'script': 'Upload.ashx',
        'folder': 'uploads',
        'fileDesc': 'Image Files',
        'fileExt': '*.jpg;*.jpeg;*.gif;*.png',
        'multi': true,
        'auto': true
    });
   }
);
</script>  

and how can i use  on event handler code 

please sugggets me