frenzy/lib/frenzy_web/templates/layout/app.html.eex

<%= if get_flash(@conn, :info) do %>
  <p class="alert alert-primary" role="alert"><%= get_flash(@conn, :info) %></p>
<% end %>
<%= if get_flash(@conn, :error) do %>
  <p class="alert alert-danger" role="alert"><%= get_flash(@conn, :error) %></p>
<% end %>

<%= @inner_content %>