data = serializers.serialize("json",[Concurso.objects.get(id=instance.id)])
    for gcm in my_phone:
        values = {
                    "to": gcm.gcm_tok,
                    "collapse_key": "collapse key" ,
                    "data": data
                  }

        headers = {
                   "UserAgent":"GCMServer",
                   "ContentType":"application/json",
                   "Authorization":"key="+KEY
                  }

        p = requests.post(url="https://android.googleapis.com/gcm/send",data=values,headers=headers)