Does select box update with typeahead?

[thujone]

Hi, I'm looking for a plain JS alternative to various jquery-based typeahead/autocomplete plugins like Selectize or Select2 or Chosen2. Horsey looks it fits the bill perfectly -- except that in the demo, the < select> dropdown does not update as the user types; essentially, it behaves the same as an HTML select. Is this piece of the demo broken, or does the dropdown not behave the same as contenteditable fields?