allowing only super user login

I have written a django page that requires only super users to login. So I have added

foo_view = staff_member_required(foo_view)

but it doesn't cut, now I can control only allowing staff marked users to login but this doesn't cut. I have tried something like

def foo_view(request):
       if not request.user.is_superuser:
           #render some "not allowed page"
       #else render the page

but it doesn't seem to help as giving me errors.