Hi Etienne

When I open a different browser from a link in one of my pages <a href="newPage" target="_blank" . . .)

The browser windows are indistinguishable to the remote server unless you give it some way of distinguishing between HTTP transactions from the different windows. AFAICS, there are two ways of accomplishing this: using URL-based session management, or using hidden form variable session management. Cookie-based session management isn't going to distinguish between browser windows. Here are a couple of links that might be useful: - http://zdp.zope.org/portals/developers/sessionmanagement/hsm - http://www.zope.org/Members/Duncan/SessionURLs - http://www.zope.org/Members/czimmet/CookieLess If you use URL-based session tracking, your URL above becomes something like <a href="newPage?s__=as983wkj32" target="_blank" . . .> where s__=as983wkj32 is the session ID. (Disclaimer: I haven't actually *done* any of the above ;) Regards, Jean PS You might want to consider switching off HTML email when posting to the mailing list ..