fileUploadXhr

POST http://projectnirvana.runcode/guests/new 500 (Internal Server Error) jquery-1.8.1.min.js:2
send jquery-1.8.1.min.js:2
p.extend.ajax jquery-1.8.1.min.js:2
fileUploadXhr jquery.form.js:263
$.fn.ajaxSubmit jquery.form.js:200
doAjaxSubmit jquery.form.js:719
p.event.dispatch jquery-1.8.1.min.js:2
g.handle.h

--------------------------
 // XMLHttpRequest Level 2 file uploads (big hat tip to francois2metz)
    function fileUploadXhr(a) {
        var formdata = new FormData();

        for (var i=0; i < a.length; i++) {
            formdata.append(a[i].name, a[i].value);
        }

        if (options.extraData) {
            for (var p in options.extraData)
                if (options.extraData.hasOwnProperty(p))
                    formdata.append(p, options.extraData[p]);
        }

        options.data = null;

        var s = $.extend(true, {}, $.ajaxSettings, options, {
            contentType: false,
            processData: false,
            cache: false,
            type: 'POST'
        });

        if (options.uploadProgress) {
            // workaround because jqXHR does not expose upload property
            s.xhr = function() {
                var xhr = jQuery.ajaxSettings.xhr();
                if (xhr.upload) {
                    xhr.upload.onprogress = function(event) {
                        var percent = 0;
                        var position = event.loaded || event.position; /*event.position is deprecated*/
                        var total = event.total;
                        if (event.lengthComputable) {
                            percent = Math.ceil(position / total * 100);
                        }
                        options.uploadProgress(event, position, total, percent);
                    };
                }
                return xhr;
            };
        }

        s.data = null;
          var beforeSend = s.beforeSend;
          s.beforeSend = function(xhr, o) {
              o.data = formdata;
            if(beforeSend)
                beforeSend.call(o, xhr, options);
        };
        $.ajax(s);
    }