title: How do I toggle Jquery validation using Ignore attribute?
body: <p>I have a panel which is toggled visible/invisible on clicking a button.
  Say the panel has extra fields, I'd like to turn off validation on those fields when the panel is hidden, but turn them back on when shown.</p>
  
  <p>I've seen the 'Ignore' option of the Jquery validation plugin, but I'm wondering how I'd go about re-enabling it after the panel is shown again.</p>