.

physics/views.py

@@ -325,8 +325,10 @@ def exam_take(request, pk, sk, cid, passcode=None):
     if exam.valid_users.exists():
         user = exam.valid_users.filter(cid=cid).first()
 
-        if not user or user.passcode != passcode:
+        if not user:
             raise Http404("Exam not found")
+        if user.passcode != passcode:
+            raise Http404("Invalid passcode")
 
     question = exam.exam_questions.all()[sk]
 
@@ -348,15 +350,23 @@ def exam_take(request, pk, sk, cid, passcode=None):
             answer.exam = exam
             # answer.published_date = timezone.now()
             answer.save()
+
+        kwargs = {
+            "pk": pk,
+            "cid" : cid
+        }
+        if passcode is None:
+            kwargs["passcode"] = passcode
+
         if "next" in request.POST:
-            return redirect("physics:exam_take", pk=pk, sk=pos + 1, cid=cid)
+            return redirect("physics:exam_take", sk=pos + 1, **kwargs)
         elif "previous" in request.POST:
-            return redirect("physics:exam_take", pk=pk, sk=pos - 1, cid=cid)
+            return redirect("physics:exam_take", sk=pos - 1, **kwargs)
         elif "finish" in request.POST:
-            return redirect("physics:exam_finish", pk=pk, cid=cid)
+            return redirect("physics:exam_finish", **kwargs)
         elif "goto" in request.POST:
             return redirect(
-                "physics:exam_take", pk=pk, sk=int(request.POST.get("goto")), cid=cid
+                "physics:exam_take", sk=int(request.POST.get("goto")), **kwargs 
             )
     else:
         form = CidUserAnswerForm(instance=answer)