Can anyone shed some light on this problem? I am working on a site where the screen is divided into a pair of frames -- a left index frame and a workspace frame. The left index consists of links which select pages to be loaded into the workspace. The target pages need to know the index that selected them. Workspace selection is many one. I wrote a small python script that takes a parameter, plants the parameter value as a cookie, and then redirects to URL1. The links in the left index frame thus look like <a href="some/source/setCookie?cookie=value" target=workspace B> The setCookie script is very simple request = container.REQUEST RESPONSE = request.RESPONSE RESPONSE.setCookie('myCookie', cookievalue ) RESPONSE.redirect(request.URL1) The results are mixed. I constructed a little test case and have tried it on four different browsers. It works on some and not on others. All redirect to the right place, but some of the browsers don't set the cookie on the flyB. This is all running on a vanilla Zope 2.5 installation using Zope's native server. Wisdom and suggestions for a workaround greatly appreciated. Using this technique will greatly simplify the site.