Topic: Problem with Ajax

I have form and an ajax call in my application.js

  $('#mynote').submit(function() {
    var valuesToSubmit = $(this).serialize();
                alert('test');
      $.ajax({
         type: "POST",
         url: "/mirror/setnote",
         data: valuesToSubmit,
       });

       return false
  });

My controller:

  def setnote
    @mynote = Note.find_by_mirror_id_and_user_id(session[:mirror_id],session[:user_id])
    @mynote.note = params[:note]
    @mynote.save
  end

It run the method but why doesn't the alert work?