title: ExtJS combo-box value field
body: <p>I'm using ExtJS in CodeIgniter (a PHP framework)</p>
  
  <p>I want to store the <code>valueField</code> of a <code>combobox</code> in a database. I set <code>displayField:'name', valueField:'id'</code> for the combobox, but when i used <code>$this-&gt;input-&gt;post(combofield name);</code> it is returning the <code>displayField</code> instead.</p>
  
  <p>How am I able to get the <code>valueField</code>?</p>