Javascript form won't submit

I have been using the uploader as provided by http://www.hoppinger.com/blog/2010/05/28/file-upload-progress-bar-with-phpapc-and-javascript/ and have since applied it to one of my forms and whilst the progress meter works, the submit function doesn't fire on successful upload.

The full code of what I am using is below:

JS

get_progress.php

uploader.php

As far as I can tell, in my limited experience, this is the function that handles the submit:

postUpload : function(o_data)
 {
     // Loop through every input and set json response in hidden input
     this.a_inputs.each((function(o_input)
         {
             var s_name = o_input.get('name');
             var s_value = '';
 
             if(o_file = o_data.files[s_name])
             {
                 s_value = JSON.encode(o_file);
             }
 
 
             var o_jsonInput = new Element('input',{'type': 'hidden','name':o_input.origName,'value':s_value}).replaces(o_input);
 
 
         }).bind(this));
 
     // Make form "original" again by purging elements and resetting attributes
     this.revertSubmit();
     this.o_form.submit();
 },
 

I noticed that the submit was this.o_form.submit(); rather than this.form.submit(); and checked it out and he has declared o_form : {} at the top of the class, so I assume that his syntax is correct but I have no real idea.

Prior to my implementing this progress tracker the form worked perfectly, so this has got me quite frustrated.

Essentially what has gone wrong, I can only assume that it's something as simple as a missing ; or similar mistake.

If you get a 404 on the submit that means it worked. I have temporarily unblocked the page for troubleshooting.

As it may be relevant, my site uses WordPress.

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