Post FormData not working in IE9

The following code does not send file data to the server in IE9.

FormData

() the object looks like a problem, but not sure how to resolve it.

I have used form.serialize()

but this is not a file upload.

I am hesitant to implement a JQuery file loader just for this function. Is there an easy way to load a file, similar to FormData ()?

    // HTML
    <form name='aform' action='upload.php'>
           <input type='file' name='afile'>
           <input type='text' name='qty' value='1'>
           <input type='hidden' name='product_id' value='7'>
           <a class='addToCartButton'>Add to cart</a>
    </form>



    // JS
    $(document).on('click', '.addToCartButton', function(event) 
    {

        var form_id = $(this).closest('form').attr('id');

        var formElement = document.getElementById(form_id);

        var odata = new FormData(formElement);        

        //var $form = $('#'+form_id);

        $.ajax({
            url: 'http://localhost/cart/add',
            data: odata, //$form.serialize(),
            type: 'POST',
            processData: false,  // tell jQuery not to process the data
            contentType: false   // tell jQuery not to set contentType            
        }).done(function(data) 
        {

            var returnObject = jQuery.parseJSON(data);

            switch(returnObject.status) {
                case 'success':
                    alert('Item added to cart');
                    break;              
                case 'error':
                    alert('An error occured');
                    break;
                case 'no_file':
                    alert('No file was detected');
                    break;                                      
            }                           

        });

        event.preventDefault();
    });