encoding it into a block of memory which it returns to the 
    Viewer library.  If the document file is open, this routine should 
    close it.  This routine is normally responsible
    destroy the UI which displays the document.</P>
<LI><STRONG>Change Document (Switch Documents):</STRONG><BR>
    <EM>Purpose:</EM> The user is jumping from document to document.  The Viewer library 
    needs the VILFile library to close the current document and open another.</LI>
<P><EM>Action:</EM> The routine should clo