JSON.stringify($('#categoryForm').serializeObject()

/**
     * 自動將form表單封裝成json物件
     */
    $.fn.serializeObject = function() {
        var o = {};
        var a = this.serializeArray();
        $.each(a, function() {
            if (o[this.name]) {
                if (!o[this.name].push) {
                    o[this.name] = [ o[this.name] ];
                }
                o[this.name].push(this.value || '');
            } else {
                o[this.name] = this.value || '';
            }
        });
        return o;
    };