title: Magento Admin Grid is Empty
body: <p>I am trying to create a custom module.When i click a module menu,empty grid is <a href="http://postimage.org/image/6s48w45wr/" rel="nofollow">displaying</a>.Log is not showing any errors</p>
  
  <p>Grid.php
      
  
  <pre><code>class Training_Banners_Block_Adminhtml_Banners_Grid extends Mage_Adminhtml_Block_Widget_Grid
  {
      public function __construct()
      {
  
          parent::__construct();
          $this-&gt;setId('bannersGrid');
          $this-&gt;setDefaultDir('ASC');
          $this-&gt;setDefaultSort('banner_id');
          $this-&gt;setSaveParamatersInSession(true);
  
  
      }
  
      protected function _prepareCollection()
      {
          $collection=Mage::getModel('banners/manage')-&gt;getCollection();
          $this-&gt;setCollection($collection);
          Mage::log(var_dump($collection));
          return $collection;
      }
  
      protected function _prepareColumns()
      {
  
          $this-&gt;addColumn('banner_id', array(
              'header'    =&gt; Mage::helper('banners')-&gt;__('ID'),
              'align'     =&gt;'right',
              'width'     =&gt; '50px',
              'index'     =&gt; 'banner_id'
          ));
  
          $this-&gt;addColumn('name', array(
              'header'    =&gt; Mage::helper('banners')-&gt;__('Name'),
              'align'     =&gt;'left',
              'index'     =&gt; 'name'
          ));
          return parent::_prepareColumns();
      }
  }
  </code></pre>
  
  <p>banners.xml</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;layout version="0.1.0"&gt;
      &lt;adminhtml_banners_index&gt;
          &lt;reference name="content"&gt;
              &lt;block type="banners/adminhtml_banners" name="training.banners" /&gt;
          &lt;/reference&gt;
      &lt;/adminhtml_banners_index&gt;
  &lt;/layout&gt;
  </code></pre>
  
  <p>Controller </p>
  
  <pre><code>&lt;?php
  
  class Training_Banners_Adminhtml_BanneradminController extends Mage_Adminhtml_Controller_Action
  {
      public function _initAction()
      {
           $this-&gt;loadLayout()-&gt;_setActiveMenu('banners/banners')
           -&gt;_addBreadcrumb(Mage::helper('adminhtml')-&gt;__('Banners Manager'), Mage::helper('adminhtml')-&gt;__('Banners Manager'));
          return $this;
      }
  
       public function indexAction() 
       {
          $this-&gt;_initAction();
          $this-&gt;loadLayout();      
          $this-&gt;_addContent($this-&gt;getLayout()-&gt;createBlock('banners/adminhtml_banners'));
          $this-&gt;renderLayout();
      }
  }
  </code></pre>