fgl_dialog_getbufferstart()
Returns the row offset of the page to feed a paged display array.
Syntax
fgl_dialog_getbufferstart()
  RETURNS INTEGER
Usage
The FGL_DIALOG_GETBUFFERSTART() function returns the
 record list offset to be used to fill a page of a DISPLAY
 ARRAY running in  paged mode.
This function must be called in the context of the ON FILL
 BUFFER trigger. The returned value is undefined if the function
 is used outside this trigger.