title: Set selected value in form of zend framework
body: <p>I created a form in zend framework. Here I want to set selected value from option while editing record. For example record have group id value 3.<br>
  This works fine in while adding record and while editing record i am not getting selected to third option.<br>
  I wrote below code but its not working.</p>
  
  <pre><code>   $group_id = $this-&gt;createElement('select','group_id');
     $group_id-&gt;setLabel('Category:')
                 -&gt;addMultiOptions(array(
                  '1' =&gt; 'A',
                  '2' =&gt; 'B', 
                  '3' =&gt; 'C',
                  '4' =&gt; 'D'                       
                      ))               
             -&gt;setRequired(true)
             -&gt;setDecorators(array('ViewHelper','Errors'));
     $group_id-&gt;setValue(3);
  </code></pre>
  
  <p>adminController.php</p>
  
  <pre><code>$id =  $this-&gt;_request-&gt;getParams('id');        
  $row = $content-&gt;find($id)-&gt;toArray();
  $form-&gt;populate($row[0]);
  </code></pre>
  
  <p>this populates data in all the fields only not setting selected for drop down.
  Here 3rd option should show selected but always 1st option is showing selected.</p>
  
  <p>Please let me know if i am missing anything here.</p>