def edit_user(request, membership, user=None):
    """ Edit an existing user, or add a new one if no user specified
    """

    # Make sure that we are attempting to attach to a valid
    # membership.
    try:
        membership = Membership.objects.get(id=membership)

    except ObjectDoesNotExist:
        error = "That Membership does not appear to exist."
        return error_404(request, error)

    # And make sure that we're talking about a valid user, if user was
    # specified.
    if user:
        user = int(user)
        try:
            user = User.objects.get(id=user)
            profile = UserProfile.objects.get(user=user)
            
        except ObjectDoesNotExist:
            error = """That user does not exist, or you are attempting
            to edit a user without a profile (you must use the admin
            interface to edit this sort of user)."""
            return error_404(request, error)

    if request.method == 'POST':
        if user:
            # save changes to an existing user
            user_form = UserForm(request.POST, instance=user)
            profile_form = UserProfileForm(request.POST, instance=profile)
            if user_form.is_valid() and profile_form.is_valid():
                user = user_form.save()
                profile = profile_form.save()

                return HttpResponseRedirect(
                    '/memberships/' + str(membership.id) + '/view/'
                    )
            else:
                template = 'edit_user.html'
                ctxt = { 
                    'request' : request, 
                    'membership' : membership,
                    'user' : user.id,
                    'edit_user' : user_form,
                    'edit_profile' : profile_form,
                    'page_name' : 'Edit User',
                    'media_url' : MEDIA_URL,
                    }
                return render_to_response(template, ctxt)


        else:
            # save a new user
            user_form = UserForm(request.POST)
            profile_form = UserProfileForm(request.POST)
            if user_form.is_valid() and profile_form.is_valid():
                user = user_form.save()
                profile = profile_form.save(commit=False)
                profile.user = User.objects.get(id=user.id)
                profile.membership = membership
                profile.save()
                profile_form.save_m2m()

#               try:
                # Try to send an email w/ password reset link to
                # the user
                subject = "Boston Mycological Club Account "
                subject += "Created"
                email_template = 'registration/new_user_email.html'
                ctxt = { 'user' : user, 'media_url' : MEDIA_URL, }
                message = loader.get_template(email_template)
                message = message.render(Context(ctxt))

                send_mail(subject, message, SERVER_EMAIL, 
                          [user.email], fail_silently=False,
                          )
#                except:
#                    error = "Account created, but email was not sent"
#                    return error_404(request, error)

                return HttpResponseRedirect(
                    '/memberships/' + str(membership.id) + '/view/'
                    )
                

            else:
                template = 'edit_user.html'
                ctxt = { 
                    'request' : request, 
                    'membership' : membership,
                    'user' : None,
                    'edit_user' : user_form,
                    'edit_profile' : profile_form,
                    'page_name' : 'Create User',
                    'media_url' : MEDIA_URL,
                    }
                return render_to_response(template, ctxt)

    elif user:
        template = 'edit_user.html'
        ctxt = { 
            'request' : request, 
            'membership' : membership,
            'user' : user.id,
            'edit_user' : UserForm(instance=user),
            'edit_profile' : UserProfileForm(instance=profile),
            'page_name' : 'Edit User',
            'media_url' : MEDIA_URL,
            }
        return render_to_response(template, ctxt)

    else:
        # return a  blank user form
        template = 'edit_user.html'
        ctxt = { 
            'request' : request, 
            'membership' : membership,
            'user' : None,
            'edit_user' : UserForm(),
            'edit_profile' : UserProfileForm(),
            'page_name' : 'Create User',
            'media_url' : MEDIA_URL,
            }
        return render_to_response(template, ctxt)