<ul class="nav">
   <% if user_signed_in? %>
   	<li><%= link_to "Missions", missions_path  %></li>
   <% else %>
   	<li><%= link_to "About", start_about_path  %></li>
   	
   <% end %>
</ul>

<ul class="nav pull-right">
	<% if user_signed_in? %>
		<li class="dropdown">
			<a href="#" class="dropdown-toggle" data-toggle="dropdown">
				<% if current_user.username %>
					<%= current_user.username %> <b class="caret"></b>
				<% else %>
					<%= current_user.email %> <b class="caret"></b>
				<% end %>
			</a>
		    	<ul class="dropdown-menu">
	  			<li><%= link_to 'Edit profile', edit_user_registration_path %></li>
	  			<li><%= link_to "Logout", destroy_user_session_path, method: :delete %></li>
			</ul>
		</li>
	<% else %>
		<li><%= link_to "Login", new_user_session_path  %></li>
		<li><%= link_to "Sign Up", new_user_registration_path  %></li>
	<% end %>
</ul>