即时消息系统:系统采用规范的J2EE架构，将Ajax技术有机地融入J2EE应用中,系统的表现层使用了DOJO的对话框页面控件,让表现层效果更加突出-Instant messaging system: The system uses standard J2EE architecture, the organic integration of Ajax technology, J2EE application, the system' s presentation layer using th