title: how to add radiobutton in wordpress widget form
body: <p>How can I add a radio button in my wordpress widget form? I have been able to add input fields that gets saved and works fine. But I am having trouble with radiobuttons. Anyone? </p>
  
  <p>This is my code for input field:</p>
  
  <pre><code>&lt;p&gt;&lt;label for="&lt;?php echo $this-&gt;get_field_id('id'); ?&gt;"&gt;&lt;?php _e('Video ID:'); ?&gt; 
      &lt;input class="widefat" id="&lt;?php echo $this-&gt;get_field_id('id');  ?&gt;" 
      name="&lt;?php echo $this-&gt;get_field_name('id'); ?&gt;" 
      type="text" value="&lt;?php echo $id; ?&gt;" /&gt;&lt;/label&gt;&lt;/p&gt;
  </code></pre>
  
  <p>and this is my radio button</p>
  
  <pre><code>&lt;input type="radio" name="video_size" value="small"&gt; Small&lt;br&gt;
      &lt;input type="radio" name="video_size" value="full" checked&gt; Full 
  </code></pre>