QueueMonitor problems

[Mazzotta Vincenzo <Mazzotta@ac.upc.es>]

Hi to all,
now i can simulate with a QueueMonitor but in the trace file there isn't
nothing....
The simulation go but the trace file is empty....
Somebody know like i get the data from queuemonitor...

The fondamentals command that i don't know :

set flow [new QueueMonitor] ;# Create a QueueMonitor object and flow is
a
                                              ;# pointer to QueueMonitor
object

$flow set-src-dst $n16 $n17  ;#Connect QueueMonitor from node16 to node
17

proc record {} {
       global flow
       global f16 ;# variable for trace

       set lenght_queue [$flow get-pkts-integrator] ;# read the size of
queue

;#  (n16->n17) in packets
       puts $f16 " $now | $lenght_queue"

Thanks in Advanced

Mazzotta Vincenzo