<% content_for :demo do %>
  <h1>This is content yielded from a content_for</h1>
<% end %>
  
<div class='demo'><%= yield_content :demo %></p>
  
<% content_for :demo2 do |fname, lname| %>
  <h1>This is content yielded with name <%= fname + " " + lname %></h1>
<% end %>
  
<div class='demo2'><%= yield_content :demo2, "Johnny", "Smith" %></div>