send object via url, apache openmeetings error 400 send special character

Question

i'm using Apache Open meetings and i have been succeed in use its method except signup because i can n't send object of the user by URL how to change setting of my server to send special character like "{" and "[" ? i have red5 server and apache-openmeetings-3.1.5 version

    function sign_up(){
    $.ajax({
        method : "GET",
        url : url_domain + "openmeetings/services/user/login",
        data : {
            user : 'omar',
            pass : 'omar'
        },
        dataType : "json",
        success : function(data) {
                    sid = data["serviceResult"]["message"];

                    user = JSON.stringify({"address":{"country":"US","deleted":false,"email":"omar-bahri-it@hotmail.com","id":null},"firstname":"soso","id":null,"languageId":1,"lastname":"sosos","login":"sosos","rights":["Room","Soap","Admin","Dashboard","Login"],"timeZoneId":"Europe/Berlin","type":"user"});       


                    //user = null;
                    confirm = false;
            $.ajax({
                method : "POST",
                url : url_domain + "openmeetings/services/user?sid="+sid+"&user="+user+"&confirm="+confirm,
                data :  {

        },
                dataType : "json",
                success : function(data2) {

                    $("#res5").html(data2);

                }
            });
        }
    });
}