title: Unchecked Checkboxes in Codeigniter
body: <p>Hi all I have a few checkboxes in Codeigniter, eg:</p>
  
  <pre><code>$data = array(
      'name'        =&gt; 'newsletter',
      'id'          =&gt; 'newsletter',
      'value'       =&gt; 'accept',
      'checked'     =&gt; TRUE,
      'style'       =&gt; 'margin:10px',
      );
  
  echo form_checkbox($data);
  </code></pre>
  
  <p>eg produces:</p>
  
  <pre><code>&lt;input type="checkbox" name="newsletter" id="newsletter" value="accept" checked="checked" style="margin:10px" /&gt;
  </code></pre>
  
  <p>is there a way that I can check in codeigniter whether the box has been selected or not in my controller? if I use $this->input->post('newsletter') and the box has been selected will the value be false? if so how can I run form validation on the data?</p>