flex下烟水晶框架的登录程序设计，用到了Viewstack等调用组件，方法或许不是最简单的，但有助于大家理解烟水晶框架结构-smoke crystal fr a me flex under the login program design, use the Viewstack so called component method may not be the most simple, but helps us to understand the fr a mework crystal stru