hi all i want Concatenate "sip:" with ip number in calling function like : but application exit with error int symbian_ua_makecall(const char* dest_url) { pj_str_t sip = pj_str("sip:"); //dst pj_str_t num = pj_str((char*)dest_url);//src pj_strcat(&sip,&num); pj_str_t uu = pj_str(sip.ptr); pjsua_call_make_call(g_acc_id, &uu, 0, NULL, NULL, &g_call_id); return PJ_SUCCESS; } that's mean i would like to send just number to symbian_ua_makecall function in the const char* dest_url variable and then concat "sip:" with number and pass new number ( "sip:" + dest_url) to pjsua_call_make_call function please help