此代码为初学xml学者必备代码，对各种实体的应用都有具体的例子，比如CDATA，PCDATA-This code for beginners XML scholars code required, application of the various entities have specific examples, such as CDATA, PCDATA etc.

路由器网页的菜单显示页面，可以通过设置，比较方便。- Display page router Webpage menu, can be set up, more convenient.this is router index page for menu