title: Select or input
body: <p>In my app I have a form for creating new trip. Model Trip has field finish_address. For setup the finish_address in I use select in simple form to select address from user's addressbook. But I want to make a better form: if there isn't necessary address, user can add it using input field. </p>
  
  <p>So I need to make form with to types of setup finish_address. How can I make it?</p>