* function: xms_lock()
*
* description: xms_lock() locks an XMS handle so that the user can treat
*     the XMS block as a regular memory address.  Thus, xms_lock()
*     returns a pointer, er, I mean a LONG value.  If xms_lock() fails,
*     the valued returned is 0000:0000, or &NULL, or just plain 0.
*-------------------------------------------------------------------------
FUNCTION &POINTER xms_lock
   PARAMETERS INT handle

   VARDEF
      UINT       ax,bx,cx,dx,ds,si,es,di,bp
      &POINTER   ptr
      UINT       hilo[2] BASED ptr
   ENDDEF

   ax = &XMS_LOCK_HND
   dx = handle
   call_driver( xms_get_driver(), ax, bx, cx, dx, si, di, bp, ds, es)
   xms_set_error( ax,bx )
   if xms_get_error() <> 0
      ptr = 0
   else
      hilo[0] = dx
      hilo[1] = bx
   endif

   return ptr

ENDPRO