[Zope] How to reload two frames?

Hello, I have a site with two frames (there is a reason for the use of frames). One frame shows an image of a newspaper page belonging to a certain date. The upper frame is a navigation bar. It can point the other frame to a different image (First page, Back, Forward, Last page) or to a different date (Previous, Next and free). The navigation frame can send the appropriate image to the image frame, but since the value of the variables (date, page) will then have changed, the navigation frame needs to reload too with the new values. Can anybody point to a way to get this done (without Javascript)? BTW does anybody know how to implement an HTML <target="framename"> into a <dtml-call "RESPONSE.redirect(foo)">? Cheers, Dirk