diff --git a/app/models/studium.rb b/app/models/studium.rb
index a072ced..dff014f 100755
--- a/app/models/studium.rb
+++ b/app/models/studium.rb
@@ -13,7 +13,7 @@
 #  updated_at :datetime         not null
 class Studium < ActiveRecord::Base
   attr_accessible :desc, :name, :typ, :zahl
-  has_many :modulgruppen, inverse_of: :studium, :class_name => "Modulgruppe"
+  has_many :modulgruppen, inverse_of: :studium, :class_name => "Modulgruppe", :dependent => :destroy
   has_many :semester, :dependent => :destroy
   
   validates :typ, :inclusion => {:in => ["Bachelor","Master"] }
diff --git a/app/views/moduls/show.html.erb b/app/views/moduls/show.html.erb
index 5190cfc..45f598a 100755
--- a/app/views/moduls/show.html.erb
+++ b/app/views/moduls/show.html.erb
@@ -1,16 +1,28 @@
 
-<% @modul.modulgruppen.each do |g| %>
 <ul class="breadcrumb">
-<li>
-<%= link_to g.studium.name  , studium_path(g.studium)%> <span class="divider">/</span></li>
-<li><%= link_to g.name , modulgruppe_path(g)%></li>
-<%end%>
+  <% @modul.modulgruppen.each do |g| %>
+    <% if !g.nil? %>
+      <li>
+	<% if !g.studium.nil? %>
+	  <%= link_to g.studium.name  , studium_path(g.studium) %> 
+	  
+	<% else %>
+	  <li>Studium fehlt!
+	<% end %>
+	<span class="divider">/</span></li>
+      <li><%= link_to g.name , modulgruppe_path(g)%>
+      <% else %>
+      <li>Modulgruppe Fehlt
+    <%end %>
+     <span class="divider">/</span> </li>
+    <%end%>
+   
 </ul>
 
 <p id="notice"><%= notice %></p>
 <%= render @modul %>
 
-
-<%= link_to 'Add LVA', new_lva_path(:modul_id =>@modul.id) %>
-<%= link_to '<i class="icon-pencil"></i>'.html_safe+ I18n.t("common.edit") , edit_modul_path(@modul) %>
-<%= link_to "Loeschen", [@modul],:method=>:delete ,:data => {:confirm =>"Are you sure" } %>
+<%= render 'layouts/pretty_toolbar' %>
+<% # link_to 'Add LVA',  %>
+<% # link_to '<i class="icon-pencil"></i>'.html_safe+ I18n.t("common.edit") , edit_modul_path(@modul) %>
+<% # link_to "Loeschen", [@modul],:method=>:delete ,:data => {:confirm =>"Are you sure" } %>