PHP / MVC & layout question

Hello, the Zend Framework, as others, offers a MVC implementation for PHP. I guess my understanding of this is right, but I still have a question. Maybe you can help. Depending on the request, a controller is called. This can do various stuff w/o model(s), and then a view is displayed. That is, only one vue is displayed at a time. We use this happily into applications where input or list forms are displayed one at a time. The top banner template is included into every application view so that is will always be displayed. But I do not like the idea to embed (include) the top banner template into every view. The problem is even more obvious when we want to create a 'portal' layout, displaying many information panels, which should be splitted into many models/views. For example, a portal homepage may display a login form, a news feed, a banner, a footer, a poll, etc. When the user enters a bad username into the login form, we should re-display the portal page and provide the error message near the login form. So, the request to the login controller should be able to re-display the complete layout. How do you handle this? frames? iframes? ajax? other? thanks for your interest. Vincent