which you previously filled with state information.</P>

<DT><STRONG>Detach (Save to State)</STRONG></DT>
<DD>This routine is responsible for allocating and filling a block of 
    memory with state information--information which may later be used 
    to restore from state.  This routine should also close the document 
    file and discard the document-display UI.</DD>
<DT><STRONG>Change Document (Switch Documents)</STRONG></DT>
<DD>This routine is responsible for switching between two documents by  
    c