Prototype Window - Gallery2

I have a Gallery2 photo gallery script source: http://gallery.menalto.com/ I would like a Prototype Window added source: Specifics: If the user is not logged in and attempts to maximize a thumbnail, a prototype window should appear prompting user for login/registration in order to maximize the photo. An example of this window can be seen at Going.com (Click Join Now). If it is easier to create a new gallery script with this addition, place a bid an…