title: How to add back the "loading" Element after removed it from Parent?
body: <p>Ok, in <code>war/MyProject.html</code>, I have:</p>
  
  <pre><code>&lt;body&gt;
     &lt;div id="loading"&gt;   
          &lt;div id="waitingForLoading"&gt;&lt;/div&gt;
              &lt;BR/&gt;
          &lt;img src="../images/loading.gif" /&gt;
  
    &lt;/div&gt;
  ...
  &lt;/body&gt;
  </code></pre>
  
  <p>in <code>MyProject.java</code></p>
  
  <pre><code>public class OfflineMatching implements EntryPoint {
     @Override
     public void onModuleLoad() {
          // this code works fine
          if(DOM.getElementById("loading")!=null){
  
              DOM.getElementById("loading").removeFromParent();
          }
  
  
          Button myButton=new Button("Enter Main Page");
          RootPanel.get().add(myButton);
          myButton.addClickHandler(new ClickHandler(){
  
             @Override
             public void onClick(ClickEvent event) {
                 // this code does not work
                 if(DOM.getElementById("loading")==null){
                   DOM.appendChild(RootPanel.getBodyElement(), DOM.createElement("loading"));
                 }
             }
          });
     }
  }
  </code></pre>
  
  <p>So, did i do anything wrong?
  Why this code does not work?</p>
  
  <pre><code> // this code does not work
             if(DOM.getElementById("loading")==null){
               DOM.appendChild(RootPanel.getBodyElement(), DOM.createElement("loading"));
             }
  </code></pre>