if submission.key != key:
         return render(request, 'wtem/key_not_found_before.html')
     else:
     if submission.key != key:
         return render(request, 'wtem/key_not_found_before.html')
     else:
     if submission.key != key:
         return render(request, 'wtem/key_not_found.html')
 
     if submission.key != key:
         return render(request, 'wtem/key_not_found.html')
 
     i, exercise = submission.current_exercise()
     if not exercise:
         return render(request, 'wtem/thanks_single.html')
     i, exercise = submission.current_exercise()
     if not exercise:
         return render(request, 'wtem/thanks_single.html')