title: How to move between panels in Sencha touch
body: <p>When moving between panels I get the following error</p>
  
  <pre><code>[WARN][Ext.Component#constructor] Registering a component with a id (`logOutButton`) which has already been used. Please ensure the existing component has been destroyed (`Ext.Component#destroy()`. 
  </code></pre>
  
  <p>I can go back to the previous screen but the cannot go forward again without getting the above error.</p>
  
  <p>To combat this I have tried using the code below, but it does not work. Can anyone help me out?</p>
  
  <pre><code>var loginView = Ext.getCmp('login');
      if(!loginView){
         Ext.getCmp('loginTest2').destroy(); 
        loginView = Ext.create('com.view.Login');
    }
  
    Ext.Viewport.setActiveItem('login');
  </code></pre>
  
  <p>I also tried:</p>
  
  <pre><code>if(Ext.getCmp('login')){
       Ext.Viewport.setActiveItem('Login');
    }else{
  
      Ext.Viewport.setActiveItem(Ext.create('com.view.Login'));
    }
  </code></pre>
  
  <p>Neither of these work and result in the same error and a blank screen. I am using Sencha Touch 2.</p>