diff --git a/00_example_render_byid/__init__.py b/00_example_render_byid/__init__.py
index 865f8d0..7c6874b 100644
--- a/00_example_render_byid/__init__.py
+++ b/00_example_render_byid/__init__.py
@@ -230,15 +230,16 @@ def debug():
 def tasks(queue, args, idlist, skiplist):
     # iterate over all events extracted from the schedule xml-export
     for event in events(scheduleUrl):
-        if 000000 in idlist:
-            continue
         if event['room'] not in ('Chirurgie (Saal 1.04)', 'Kreißsaal (Saal 1.11)'):
-            print("skipping room %s (%s)" % (event['room'], event['title']))
+            print("skipping room %s (%s [%s])" % (event['room'], event['title'], event['id']))
             continue
-        if not (idlist==None):
-            if int(event['id']) not in idlist:
-                print("skipping id %s (%s)" % (event['id'], event['title']))
-                continue
+        if not (idlist==[]):
+                if 000000 in idlist:
+                        print("skipping id (%s [%s])" % (event['title'], event['id']))
+                        continue
+                if int(event['id']) not in idlist:
+                        print("skipping id (%s [%s])" % (event['title'], event['id']))
+                        continue
 
         # generate a task description and put them into the queue
         queue.put(Rendertask(
diff --git a/make.py b/make.py
index e5d642f..47b4307 100755
--- a/make.py
+++ b/make.py
@@ -100,6 +100,13 @@ if renderlib.debug:
 # threaded task queue
 tasks = Queue()
 
+#initialize args.id and args.skip, if they are not given by the user
+if (args.id==None):
+	args.id = []
+
+if (args.skip==None):
+	args.skip = []
+
 # call into project which generates the tasks
 project.tasks(tasks, projectpath, args.id, args.skip)