server.registerMBean(my, mbean);
server.registerMBean(mon1, mon1n);
server.registerMBean(mon2, mon2n);
mon1.addObservedObject(mbean);
mon1.setGranularityPeriod(60000); // 60 sec...
mon1.setObservedAttribute(attr);
mon1.setDifferenceMode(true);
check(attr,server,mon1n,mbean);