jquery ui autocomplete: trigger only when item is not selected

I'm trying to figure out how to make an "opposite" of a jquery ui select. When someone does not select an option and just types "jquery something" output will be: "new input: jquery something". However when the "jquery" is selected it would be nice to somehow only have "selected from list: jquery", and prevent the keypress propogation. However, both events fire. I'm trying to make it one or the other.

<input class="test" type="text" />

<script>
$('.test').autocomplete({
    select: function (event, ui) {
        alert('selected from list: ' + ui.item.label);
        event.preventDefault();
        return false;
    },
    source: ["jquery", "jquery ui", "sizzle"]
});
$('.test').live('k开发者_开发问答eypress', function (e) {
    if ((e.which && e.which == 13) || (e.keyCode && e.keyCode == 13)) {
        alert('new input: ' + $(this).val());
    }
});
</script>

This is going with the assumption that the "enter" key is used to select an option from the ui's menu.

You could accomplish this using the autocompletechange event. Using this event, you can determine if the user selected an option or typed something in that wasn't on the list:

$("#auto").autocomplete({
    source: ['hi', 'bye', 'foo', 'bar'],
    change: function(event, ui) {
        console.log(this.value);
        if (ui.item == null) {
            $("span").text("new item: " + this.value);
        } else {
            $("span").text("selected item: " + ui.item.value);
        }
    }
});

Example: http://jsfiddle.net/Ne9FH/