text: (function ( $ ) {
    $.fn.update = function(){
      var newElements = $(this.selector),i;    
      for(i=0;i<newElements.length;i++){
        this[i] = newElements[i];
      }
      for(;i<this.length;i++){
        this[i] = undefined;
      }
      this.length = newElements.length;
      return this;
    };
  })(jQuery);