resizing scrolling windows

[vctr@engin.umich.edu (Michel Victor)]

In the examples folder there is a program called grapher.lisp that 
uses the scrolling window class defined in scrolling-windows.lisp.  
Does anyone know how to change the scrolling area of one of these 
windows after it has been created (when, for example, the graph  
becomes larger)?  There is a function in scrolling-windows.lisp that  
changes the on-screen area of the window, but there is nothing that 
changes the scrollable area inside the window.  Also, is it possible for 
a function to change the scroll position a scrolling window?