I shall be so bold, to suggest slightly improved isEmptyObject() ...

/*

 currently in jQuery

 isEmptyObject : function(obj) {

            for (var name in obj) {

                return false;

            }

            return true;

        } ,

*/

/*

   return undefined on any object that is not "object" or "function"

   also ignore the possible prototype chain

*/

// slightly improved

isEmptyObject : function (object) {

    if (typeof object !== 'object' && typeof object !== 'function') return ;

        for (var name in object) {

            if (Object.prototype.hasOwnProperty.call(object,name)) {

                return false;

            }

        }

    return true;

};