title: removing field in form dynamically sencha 2
body: <p>i am using sencha touch 2.0 and want to create a button '+' and '-',to add and remove a field dynamically,i have figured out the add part using</p>
  
  <blockquote>
    <p>this.getForm().insert({...});</p>
  </blockquote>
  
  <p>but remove part does not hide the field.</p>
  
  <blockquote>
    <p>this.getForm().remove('...');</p>
  </blockquote>