Autocomplete disallow free text entry?

Question

Is it possible to disallow free text entry in the JQuery UI autocomplete widget?

eg I only want the user to be allowed to select from the list of items that are pre

Answer 1

Old question, but here:

    var defaultVal = '';
    $('#selector').autocomplete({
        source: url,
        minlength: 2,
        focus: function(event, ui) {
            if (ui != null) {
                defaultVal = ui.item.label;
            }
        },
        close: function(event, ui) {
            $('#searchBox').val(defaultVal);
        }
    });