From Jquery-ui autocomplete to typeahead.js

I am migrating my app to twitter-bootstrap and i would like to replace my jquery-ui autocomplete with typeahead.js.

It would be better to use the feature embedded in twitter-bootstrap but i am ok with the extra typeahead plugin if necessary.

My problem is that i have trouble reproducing the current behaviour especially with the absence of results.

How would you do something like that?

$("#search").autocomplete({
           source : myUrl,
            delay : 100,
            minLength : 2,
            select : function(event, ui) {
              // do whatever i want with the selected item
            },

            response : function(event, ui) {
                if (ui.content.length === 0) {
                    ui.content.push({
                        label : "No result",
                        value : customValue
                    });
                }
            }
        });

Basically, if there is no result, i want to display a custom message in the component.

Thanks!