title: Can you restrict entering invalid keystrokes with jQuery UI autocomplete combobox?
body: <p>When using <a href="http://jqueryui.com/demos/autocomplete/#combobox" rel="nofollow noreferrer">the jQuery UI autocomplete</a> <strong>combobox</strong>, I would thought there would be an option to force only a valid key entry based on the list.  Is there any way to not allow invalid keys, so you can only enter valid items in the list?  Also, is there a way to set a default value of the combobox?</p>
  
  <p>If my list has (C#, Java, Python)</p>
  
  <p>I can start typing "abcds . ." and it lets me type it in.  I want only valid entries to be allowed.</p>