[Sems] Problem when redirecting to Sems from Opensips

[Eli Hayun]

Hi
I am trying to get MusicOnHold. When I find out an HOLD request I am
doing the following in OpenSips

        append_hf("P-App-Name: announcement\r\n");
        rewritehostport("myhost:5080");
        t_relay();
        exit;
But I am getting an error 

SIP/2.0 481 Call leg/Transaction does not exist

I think the problem is that I am in a middle of a transaction, but I
don't know how to avoid that error and actually run the application

Thanks

Eli Hayun