String callid=sip_provider.pickCallId();
int cseq=SipProvider.pickInitialCSeq();
String localtag=SipProvider.pickTag();
//String branch=SipStack.pickBranch();
Message req=createRequest(sip_provider,SipMethods.REFER,request_uri,recipient,from,contact,callid,cseq,localtag,null,null,null);
req.setReferToHeader(new ReferToHeader(refer_to));
//if (referred_by!=null) req.setReferredByHeader(new ReferredByHeader(referred_by));
req.setReferredByHeader(new ReferredByHeader(from));
return req;
}