I've finally got my laptop (Compaq N600c) to work with ACPI to get working suspend and hibernate.
However, I can only do that as root.

For example,

#!/bin/sh
# /etc/acpi/sleepbtn.sh
# Initiates a shutdown when the power putton has been pressed.

LOGGER="/usr/bin/logger -t ACPID"
/usr/sbin/hibernate
#echo 4 > /proc/acpi/sleep
$LOGGER "Sleep button pressed"

Nothing happens when I press the button as a user. In a console,
hibernate: You need to run this as root.
Nothing happens if I type sudo hibernate.

I can hibernate through the klaptop icon as a user though.

I know its something relatively simple...

you can make it by sudo

run visudo to edit the sudoers file,its format use

BNF,and that is a list intricate.
so you'd better run
man 5 sudoers
to learn the format

last,rum sbin cmd liske this

sudo /sbin/poweroff

for some "simple" script, you could also set the uid (chmod 4755) bit and make sure the script is owned by root, it will cause the script to execute with root right. However it is not very "secure", it's better not use it on a server