don't buy the product again in case the user reloads the 'buy_thanks' page

cash/urls.py

@@ -20,6 +20,10 @@ urlpatterns = patterns('',
 	url(r'buy/(?P<product_id>\d+)/really/$', 'cash.views.buy',
 	    {'confirm': True}, name='buy_really'),
 
+	url(r'buy/thanks/$', 'cash.views.buy_thanks', name='buy_thanks'),
+
+	url(r'buy/error/$', 'cash.views.buy_error', name='buy_error'),
+
 	url(r'usersettings(/(?P<submit>\w+))?/$', 'cash.views.usersettings',
 	    name='usersettings'),
 

cash/views.py

@@ -1,6 +1,6 @@
 from django.views import generic
 from django import forms
-from django.shortcuts import render_to_response, get_object_or_404
+from django.shortcuts import render_to_response, get_object_or_404, redirect
 from django.contrib.auth.decorators import login_required
 from django.template import RequestContext
 from django.core import paginator
@@ -80,18 +80,25 @@ def buy(request, product_id, confirm=False):
 	product = get_object_or_404(Product, id=product_id)
 
 	if confirm:
-		context = RequestContext(request)
 		if request.user.account.buy_product(product, 1):
-			return render_to_response('cash/buy_thanks.html',
-									  context_instance=context)
+			return redirect('buy_thanks')
 		else:
-			return render_to_response('cash/buy_error.html',
-									  context_instance=context)
+			return redirect('buy_error')
 	else:
 		context = RequestContext(request, {'product': product})
 		return render_to_response('cash/buy_confirm.html',
 		                          context_instance=context)
 
+@login_required
+def buy_thanks(request):
+	context = RequestContext(request)
+	return render_to_response('cash/buy_thanks.html', context_instance=context)
+
+@login_required
+def buy_error(request):
+	context = RequestContext(request)
+	return render_to_response('cash/buy_error.html', context_instance=context)
+
 class UserSettingsForm(forms.Form):
 	daily_digest = forms.BooleanField(required=False,
 	                                  label=ugettext_lazy('daily digest'))