如何在Laravel中插入可编辑的下拉列表？

I know how to add dropdown in Laravel, but what about editable dropdown?

{{ Form::select('unit', $units, Input::old('unit'), ['class' => 'form-control'])}}

Finally, I achieved like this(I am using Laravel 4 now, if you use 5, you should change {{ }} to {!! !!}).

var availableNames = {{ json_encode($itemnames) }};

$("input#name").autocomplete({
    source: availableNames,
    minLength: 0,
    delay: 0
}).focus(function () {
    //reset result list's pageindex when focus on
    $(this).autocomplete("search");
});