1. A graphical user interface for a computer, said interface including graphical objects that are displayed on a monitor of the computer and that are accessed by users to control the operation of the computer, said interface comprising a plurality of definitions that are respectively associated with said graphical objects, each of said definitions comprising a hierarchical set of software code modules, including: a first code module at one level of the hierarchy which defines the structural relationship of elements that constitute a displayed image of the graphical object; and a second code module at a lower level of the hierarchy which depends from said first code module, said second code module defining an appearance for each of the elements in the image of the graphical object to be displayed on the monitor.