Access request in django custom template tags

My code in myapp_extras.py:

from django import template

register = template.Library()

@register.inclusion_tag('new/userinfo.html')
def address():
    address = request.session['address']
    return {'address':address}

in 'settings.py':

TEMPLATE_CONTEXT_PROCESSORS =(
    "django.core.context_processors.auth",
    "django.core.context_processors.debug",
    "django.core.context_processors.i18n",
    "django.core.context_processors.media",
    'django.core.context_processors.request'
)

but I got an error:

TemplateSyntaxError at /items/

Caught an exception while rendering: global name 'request' is not defined

Original Traceback (most recent call last):
  File "C:\Python25\lib\site-packages\django\template\debug.py", line 71, in render_node
    result = node.render(context)
  File "C:\Python25\lib\site-packages\django\template\__init__.py", line 915, in render
    dict = func(*args)
  File "C:\p4\projects\myproject\..\myproject\invoice\templatetags\myapp_extras.py", line 9, in address
    address = request.session['address']
NameError: global name 'request' is not defined

I referenced this one In Django, is it possible to access the current user session from within a custom tag?.