1. A method comprising: generating for display, with a set-top box, a display item having a first program function, wherein the first program function is based on a non-markup language, and the first program function is preprogrammed on the set-top box; receiving, with the set-top box, a markup language document, from a remote source; interpreting the markup language document, with the set-top box, to determine that the markup language document assigns a second program function to the display item; updating the set-top box based on the markup language document such that the display item has the second program function; and generating for display, with the set-top box, the display item having the second program function.