* function: xms_avail()
*
* description: xms_avail() returns the number of kBytes available in
*     extended memory.  Note that since we return it as an int, this
*     function will return a negative value if you have between 32M
*     and 64M of memory.  It will fail altogether if you have more than
*     64M.  However, most 386 & 486's can access only 16M.
*-------------------------------------------------------------------------
FUNCTION INT xms_avail

   VARDEF
      UINT  ax,bx,cx,dx,ds,si,es,di,bp
   ENDDEF

   ax = &XMS_MEM_AVAIL
   call_driver( xms_get_driver(), ax, bx, cx, dx, si, di, bp, ds, es)
   xms_set_error( ax, bx )

   return dx

ENDPRO