running error of a new agent?

[Ghassan Chaddoud <Ghassan.Chaddoud@loria.fr>]

Dear ns-isers,
when I run my ns script using a new agent grpkey I find this error:
----------------------------------
Program received signal SIGSEGV, Segmentation fault.
0x805e97d in Agent::send (this=0x83ec360, p=0x83f03e8, h=0x0) at
agent.h:71
71              void send(Packet* p, Handler* h) { target_->recv(p, h);
}
----------------------------------
the error comes from "send"( the send of the class agent) in this code:
int GrpKeyAgent::command(int argc, const char*const* argv) {
  static  int i=0; int j;  
if (argc == 2) {
    if (strcmp (argv[1], "invite") == 0) {
      //create a new packet and send it
      
      send(pkt, 0);
  }
   return (Agent::cammand(argc,argv));  
}
I don't understand why this error I use here the same "send" in ping.cc
of the tutorial. 

I'll appreciate any help 

Regards

-- 
Ghassan CHADDOUD
LORIA/INRIA-Lorraine
Campus Scientifique BP 239
54506 Vandoeuvre-les-Nancy CEDEX