title: JQuery autocomplete: how to force selection from list (keyboard)
body: <p>I am using JQuery UI autocomplete.  Everything works as expected, but when I cycle with the up/down keys on the keyboard, I notice that the textbox is filled with items in the list as expected, but when I reach the end of the list and hit the down arrow one more time, the original term that I typed shows up, which basically allows the user to submit that entry.</p>
  
  <p>My question: Is there a simple way to limit the selection to the items in the list, and remove the text in the input from the keyboard selection?</p>
  
  <p>eg: if I have a list that contains <code>{'Apples (AA)', 'Oranges (AAA)', 'Carrots (A)'}</code>, if the user types 'app', I will automatically select the first item in the list ('Apples (AA)' here), but if the user presses the down arrow, 'app' shows up again in the textbox.  How can I prevent that?</p>
  
  <p>Thanks.</p>