[syslinux] INCLUDE is not working

[Piavlo]

 Hi,

I try to use  the INCLUDE statement in pxellinux config file but it
complains with:
  "unknown keyword in config file"

Here is my config  file
---------------------
default gentoo
timeout 50
prompt 1

display pxelinux.cfg/default.menu

label grub
      localboot 0

include pxelinux.cfg/gentoo
--------------------

 Thanks
 Alex