All popular browsers now support a programmable document object model( DOM), and the last few versions of these browsers have added the capability to communicate directly between the client and the server, without a complete postback and round trip.

• 目前主流的浏览器都支持可编程的文档对象模型（dom）其中一些浏览器在最近的版本中增加了客户端与服务器直接交互的能力，不用完全的回发和往返。