[CentOS] no group package selection via PXE network installation

Tue Oct 15 12:26:35 UTC 2013
Riccardo Castellani <r.castellani at usl6.toscana.it>

I'm trying to install centos 6.4 on my server A (which has 512 MB ram and no
cdrom) by PXE.
I exported installation tree 'CentOS-6.4-i386-bin-DVD1.iso' via http on
server 'Z', all according to Centos howto (copied vmlinuz, pxelinux.cfg,
initrd.img , started tftpd+dhcpd services)
Boot process is OK (in text mode! I think it's a memory problem); it's
required keyboard type, time zone, network parameters, disk partitions, ...
but no installation type is required (basic, minimal, server, ...) and no
packages selection ! Installation goes on installing the packages but
without choosing them! 
I'd like to choose type of installation and the details of packages, any
options as I used directly installation dvdrom1. 
I don't want to use kickstart file !

My 'pxelinux.cfg/default' file:

timeout 9000
default menu.c32
menu title ########## PXE Boot Menu ##########
label 1
   menu label ^1) Install CentOS 6
   kernel centos64/vmlinuz
   append initrd=centos64/initrd.img repo=http://a.b.x.y/centos6
devfs=nomount ramdisk_size=152000
label 2
  menu label ^2) Boot from local drive
  localboot


What do you think ?