python - django website: As i logged out, but click on the browser backspace arrow, it display the former webpage -

the web backend written in django. logged out, click on browser backspace arrow, display former webpage; code:

def safe_exit(request):     #print request     if 'uname' in request.session , 'uid' in request.session:         del request.session['uname']         del request.session['uid']         del request.session['logged_in']     #return render_to_response('reader/login.html',{})     return httpresponseredirect('/') 

what want : should redirect login page. how achieve this, have tried use ajax user's login status, it's work, because after click on backspace arrow, use firebug listen on network, didn't send http request @ all.