title: ExtJs - Change Textfield VType dynamically
body: <p>A rather straightforward question.  No answer found anywhere.</p>
  
  <p>Using ExtJs 4.2</p>
  
  <p>I have two custom VTypes, and one textfield.  I want to change that textfield's vtype when the user clicks a radio button.</p>
  
  <p>I know that the text field has already been created so doing:</p>
  
  <pre><code>textfield.vtype = 'otherType';
  </code></pre>
  
  <p>won't do it for me.  Neither will:</p>
  
  <pre><code>Ext.apply(textField,{vtype:'otherType'});  
  </code></pre>
  
  <p>So the obvious stuff is out.  Now I'm toying with destroying and re-creating it, but (if it even works) that seems like overkill.  </p>