execute programme when receiving account packet

[Toure Mamadou]

Hi,
All i'd like to execute an external program when receiving an
Accounting-Request.
I've try

exec ipoque {
		wait = yes
		program = "/bin/sh /opt/mytest %{User-Name}"
		input_pairs = request
		output_pairs = reply
		shell_escape = yes
		output = none
		packet_type = Accounting-Request
}

But the program is not execute even if I comment packet_type =
Accounting-Request line (#packet_type = Accounting-Request).
Can someone help me please.
Regards.