1. An apparatus for presenting a sequence of user interface pages to a user, comprising: page logic associated with an initial user interface page, wherein the page logic is configured to: detect the user's activation of a control provided by the initial user interface page; and form a token representative of the activation of the control; and a navigation module providing a hierarchical tree of nodes representative of the user interface pages in the sequence, wherein the navigation module is configured to: receive the token from the page logic; and determine another user interface page to present to the user by traversing the hierarchical tree of nodes based on a navigation instruction specified by the token.