title: ReferenceError: Error #1069: Property visible not found on String and there is no default value
body: <pre><code>function item_back_click(evt:Event):void {
       var back:MovieClip = MovieClip(evt.currentTarget);
       var req:URLRequest = new URLRequest(MovieClip(back.parent).data.@link);
       var listnumber = ("listbox" + MovieClip(back.parent).data.@link);
       trace(listnumber);
       if (listnumber.visible == false) listnumber.visible = true;
  }
  </code></pre>
  
  <p><code>trace(listnumber);</code> displays <code>listbox1</code></p>
  
  <p>but</p>
  
  <pre><code>if (listnumber.visible == false) listnumber.visible = true;
  </code></pre>
  
  <p>Gives error:</p>
  
  <pre><code>ReferenceError: Error #1069: Property visible not found on String and there is no default value.
      at listbox_fla::listbox_1/item_back_click()
  </code></pre>
  
  <p>Why is this?</p>
  
  <p>and this works well:</p>
  
  <pre><code>if (listbox1.visible == false) listbox1.visible = true;
  </code></pre>