说明： 此代码是“用XML和XSLT进行高级的 Web UI设计（七）”一文的例子代码。示范如何在树形目录中添加表示层次关系的线条。使得树形目录界面可读性更好，父子节点的关系也更加清晰。主要缺点是需要处理更多的对象，同时页面上需要显示更多的图像。所幸的是浏览器加载页面文件的时间开销没有多大的变化
(this code of "using XML and XSLT advanced Web UI Design (7)," an example of the text generation yards. A demonstration of how the directory tree hierarchy said adding lines. Tree directory interface makes better readability, the relationship between father and son nodes also become clearer. The main drawback is the need to address a wider audience, while pages need to show more images. Fortunately, the browser page document load time overhead is not much change )
文件列表：
common
......\css.js
......\_vti_cnf
......\........\css.js
css
...\tree.css
...\_vti_cnf
...\........\tree.css
images
......\blank.png
......\book.gif
......\bookopen.gif
......\closedfolder.png
......\document.gif
......\I.png
......\L.png
......\Lminus.png
......\Lplus.png
......\openfolder.png
......\paper.gif
......\paper2.gif
......\T.png
......\tinybox.gif
......\Tminus.png
......\Tplus.png
index.html
tree
....\tree.js
....\tree.xml
....\tree.xsl
....\treeNestingFalse.xsl
....\treeNestingTrue.xsl
