a good idea to keep the document file open as long as the 
   the document is open--this marks the file as "in use" so that 
   the user won't try to open it and change it in another application.</P>

<P CLASS="figTitle"><STRONG>Code Display:</STRONG> Sample handlers for the four entry points</P>
<PRE>
/* VLR_OPEN       optr( ViewerParams *vp ) */
optr _pascal TVOpen( ViewerParams *vp ) {
  optr   		theTableUI;
  ReservationHandle     moreSpace;

  /* We want to request more heapspace for the app to hold al