Simplify sidebar and navigation

Check existence of supporter levels

app/views/admin/registrations/edit.html.haml

@@ -18,7 +18,7 @@
             = p.text_field :company, :placeholder => "Company/User Group/nothing", :as => :string
 
         = f.inputs "Registration Information" do
-          - if @conference.use_supporter_levels?
+          - if @conference.use_supporter_levels? and @conference.supporter_levels.length > 0
             = f.semantic_fields_for :supporter_registration do |reg|
               = reg.input :supporter_level, :as => :select, :collection => @conference.supporter_levels
               = reg.input :code, :label => "Confirmation or registration code (if applicable)"
@@ -35,11 +35,6 @@
             %br
             = f.input :social_events, :as => :check_boxes, :label => false, :collection => @conference.social_events
 
-        - if @conference.use_dietary_choices?
-          = f.inputs "Food" do
-            = f.input :dietary_choice, :collection => [["None", nil]] + @conference.dietary_choices.map {|x| [x.title, x.id]},
-                :include_blank => false, :label => "Special Dietary Restriction"
-            = f.input :other_dietary_choice, :input_html => {:rows => "2", :class => "span6"}, :label => "Other Dietary Restictions (please describe)"
         = f.action :submit, :button_html => { :value => "Edit Registration", :class => "btn btn-primary" }
 :javascript
     $("#registration_supporter_registration_attributes_supporter_level_id").change(function () {
@@ -69,4 +64,4 @@
         onSelect: function(selected) {
             $("#registration-arrival-datepicker").datepicker("option","maxDate", selected)
         }
-    });
+    });