How to access scriptData from uploadify in asp.net MVC controller?

I've got uploadify handling some file uploads on my mvc project and that part is working very nicely. I just want to know what I will need to add to my controller action to get access to scriptData variables that I am passing from the uploadify javascript.

EDIT for some more clarification:

My uploadify script is as follows:

var fileCategoryID;
$(document).ready(function() {
$('#uploadify').uploadify({
    'uploader': '../../scripts/uploadify.swf',
    'cancelImg': '../../content/images/cancel.png', 
    'script': '../../' + $('#Controller').val() + '/FileSave/' + $('#OrderID').val(),
    'folder': 'Uploads',
    'multi': true, 
    'auto': false,
    'queueSizeLimit': 5,
    'queueID': 'fileQueue',
    'displayData': 'speed',
    'fileExt': '*.pdf',
    'fileDesc': 'PDF',
    'sizeLimit': '5242880',
    'scriptData': { 'categoryID': fileCategoryID }
});
$('#fileCategory').change(function() {
    fileCategoryID = $('#fileCategory').val();
});
});

I am curious how I can access this data from within my controller action

Found an answer working through it on my own, by accepting a formcollection in my controller action i can access the categoryID parameter from the uploadify script.

EDIT for some code:

 [AcceptVerbs(HttpVerbs.Post)]
 public string FileSave(long id, HttpPostedFileBase FileData, FormCollection forms)
 {
     long catID = Int64.Parse(forms.Get("CategoryID"));

     //do something with files

     return "Upload Successful";
 }