application.html.erb

    <div id="nav">
        <% if current_user %>
        <%= link_to "Edit Profile", edit_user_path(current_user.id)%>
        <%= link_to "Logout", :logout%>
        <% else %>
        <%= link_to "Register", new_user_path%> | 
        <%= link_to "Login", :login %>
        <% end %>
    </div>