title: dual list box and jquery validation
body: <p>I am using the jquery dual listbox plugin (<a href="http://www.virtuosoft.eu/code/bootstrap-duallistbox/" rel="nofollow">http://www.virtuosoft.eu/code/bootstrap-duallistbox/</a>). I would like to add jquery validation.
  If you submit the form without having selected at least one value a message should appear. When you use a normal select tag the name of the field is always submitted, if you leave the dual listbox empty the fieldname is not posted.</p>
  
  <p>I have already asked this question at the developer but still got no answer.
  Can someone give me a clue? Thanks.   </p>