title: Ruby on Rails: how do I use a default placeholder thing in a select_tag?
body: <pre><code> &lt;%= select_tag(:services, 
                         options_from_collection_for_select(Service.all, :id, :name))%&gt;
  </code></pre>
  
  <p>And it displays all the services...</p>
  
  <p>But I want it to be something like:</p>
  
  <pre><code>Select a service
  Service1
  Service2
  Service3
  Service4
  </code></pre>