Trying to save into database from python django

I am new to django so still learning but I am trying to save values into the database but I keep getting error "name 'Message' is not defined".

views.py

def messages(request):
    if 'username' in request.session:
        username = request.session['username']
        if 'message' in request.POST:
            message1 = request.POST['message']
            savemessage = Message(message=message1)
            savemessage.save()

    template = loader.get_template('social/messages.html')
    context = RequestContext(request, {
        'appname': appname,
        'username': username,
        'loggedin': True
    })
    return HttpResponse(template.render(context))
else:
    raise Http404("User is not logged it, no access to messages page!")

models.py

class Message (models.Model):
    message = models.CharField(max_length=255)


    def _str_(self):
        return self.message