--- a/quiz/models.py	Tue Apr 20 15:31:21 2010 +0530
+++ b/quiz/models.py	Tue Apr 20 15:39:07 2010 +0530
@@ -34,6 +34,7 @@
 
     user = models.ForeignKey(User)
     event = models.ForeignKey(Event)
+    user_ip = models.CharField(max_length=15)
     
     quiz_num = models.CharField(max_length=2)
     que_remaining = models.CharField(max_length=100)

--- a/quiz/views.py	Tue Apr 20 15:31:21 2010 +0530
+++ b/quiz/views.py	Tue Apr 20 15:39:07 2010 +0530
@@ -20,6 +20,12 @@
     if user.is_authenticated():
         return redirect("/quiz/start/%s"%user.username)
 
+    try:
+        Quiz.objects.get(user_ip=ip)
+        return redirect("/quiz/complete")
+    except Quiz.DoesNotExist:
+        pass
+
     if request.method == "POST":
         form = UserRegisterForm(request.POST)
         if form.is_valid():