在webim中，如何查询在线的群组成员

//根据roomId查询room成员列表

var queryOccupants = function queryOccupants(roomId) {

    var occupants = [];//存放成员容器

    //查询获取room信息

    conn.queryRoomInfo({

        roomId : roomId,

        success : function(occs) {

            if (occs) {

                for ( var i = 0; i < occs.length; i++) {

                    occupants.push(occs[i]);

                }

            }

            //查询获取room成员信息

            conn.queryRoomMember({

                roomId : roomId,

                success : function(members) {

                    if (members) {

                        for ( var i = 0; i < members.length; i++) {

                            occupants.push(members[i]);

                        }

                    }

                }

            });

        }

    });

};