show delete dialog.

src/de/tudarmstadt/informatik/hostage/ui/fragment/RecordOverviewFragment.java

@@ -451,6 +451,8 @@ public class RecordOverviewFragment extends UpNavigatibleFragment implements Che
                         // User cancelled the dialog
                     }
                 });
+        AlertDialog dialog = builder.create();
+        dialog.show();
     }
 
     @Override