Edit details:

<%= error_messages_for 'user' %> <%= start_form_tag :controller => 'user', :action => 'edit', :display_name => @user.display_name %>
display name<%= text_field :user, :display_name, :value => @user.display_name %>
description<%= text_area :user, :description, :value => @user.description %>
home latitude<%= text_field :user, :home_lat, :value => @user.home_lat %>
home longitude<%= text_field :user, :home_lon, :value => @user.home_lon %>
<%= submit_tag 'Change' %> <%= end_form_tag %>