Django admin site not working

[melsebaey@…]

Hi,
I'm a new user for django, I started using the tutorial for ver 1.4 with python 2.7.1 on mac 10.7.3
when i try to open the admin site it' gives me the following error

DoesNotExist at /admin/
Site matching query does not exist.
Request Method: GET
Request URL: ​http://127.0.0.1:8000/admin/
Django Version: 1.4
Exception Type: DoesNotExist
Exception Value:
Site matching query does not exist.
Exception Location: /Library/Python/2.7/site-packages/Django-1.4-py2.7.egg/django/db/models/query.py in get, line 366
Python Executable: /usr/bin/python
Python Version: 2.7.1
Python Path:
['/Users/mohammedelsebaey/a/mysite1',

'/Library/Python/2.7/site-packages/Django-1.4-py2.7.egg',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages',
'/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old',
'/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload',
'/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC',
'/Library/Python/2.7/site-packages']

Server time: Sun, 15 Apr 2012 07:08:37 -0500

This is the installed applications part in the settings.py

INSTALLED_APPS = (

'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
'polls',
# Uncomment the next line to enable the admin:

'django.contrib.admin',

# Uncomment the next line to enable admin documentation:

#'django.contrib.admindocs',

)

and this is the urls.py

rom django.conf.urls import patterns, include, url

# Uncomment the next two lines to enable the admin:
from django.contrib import admin
admin.autodiscover()

urlpatterns = patterns(,

# Examples:
# url(r'^{$', 'mysite1.views.home', name='home'),
# url(r'}mysite1/', include('mysite1.foo.urls')),

# Uncomment the admin/doc line below to enable admin documentation:
# url(r'^{admin/doc/', include('django.contrib.admindocs.urls')),}

# Uncomment the next line to enable the admin:
url(r'^{admin/', include(admin.site.urls)),}

)

thanks