title: Comstum magento extention doesnt save form post value
body: <p>I'm trying to create a custom magento extension.</p>
  
  <p>It works, only 1 form field is not saved to the db.</p>
  
  <pre><code>public function saveAction()
  {
      if ($postData = $this-&gt;getRequest()-&gt;getPost()) {
          $model = Mage::getSingleton('foo_bar/baz');
          $model-&gt;setData($postData);
  
          try {
              $model-&gt;save();
  
              Mage::getSingleton('adminhtml/session')-&gt;addSuccess($this-&gt;__('The baz has been saved.'));
              $this-&gt;_redirect('*/*/');
  
              return;
          }   
          catch (Mage_Core_Exception $e) {
              Mage::getSingleton('adminhtml/session')-&gt;addError($e-&gt;getMessage());
          }
          catch (Exception $e) {
              Mage::getSingleton('adminhtml/session')-&gt;addError($this-&gt;__('An error occurred while saving this baz.'));
          }
  
          Mage::getSingleton('adminhtml/session')-&gt;setBazData($postData);
          $this-&gt;_redirectReferer();
      }
  }
  </code></pre>
  
  <p>The form:</p>
  
  <pre><code>  protected function _prepareForm()
  {  
      $model = Mage::registry('foo_bar');
  
      $form = new Varien_Data_Form(array(
          'id'        =&gt; 'edit_form',
          'action'    =&gt; $this-&gt;getUrl('*/*/save', array('id' =&gt; $this-&gt;getRequest()-&gt;getParam('id'))),
          'method'    =&gt; 'post'
      ));
  
      $fieldset = $form-&gt;addFieldset('base_fieldset', array(
          'legend'    =&gt; Mage::helper('checkout')-&gt;__('Baz Information'),
          'class'     =&gt; 'fieldset-wide',
      ));
  
      if ($model-&gt;getId()) {
          $fieldset-&gt;addField('id', 'hidden', array(
              'name' =&gt; 'id',
          ));
      }  
  
      $fieldset-&gt;addField('name', 'text', array(
          'name'      =&gt; 'name',
          'label'     =&gt; Mage::helper('checkout')-&gt;__('Name'),
          'title'     =&gt; Mage::helper('checkout')-&gt;__('Name'),
          'required'  =&gt; true,
      ));
  
       $fieldset-&gt;addField('stock', 'text', array(
          'name'      =&gt; 'stock',
          'label'     =&gt; Mage::helper('checkout')-&gt;__('stock'),
          'title'     =&gt; Mage::helper('checkout')-&gt;__('stock'),
          'required'  =&gt; true,
  
      ));
  
      $form-&gt;setValues($model-&gt;getData());
      $form-&gt;setUseContainer(true);
      $this-&gt;setForm($form);
  
      return parent::_prepareForm();
  }  
  }
  </code></pre>
  
  <p>The value of the 'stock field is not saved'.</p>
  
  <p>I checked that the column stock exist in the db and en name's are the same.</p>
  
  <p>Does anyone know what I'm doing wrong?</p>
  
  <p>Thanks in advance.</p>