xml数据筛选，请帮忙！

[sweig0721]

<?xml version="1.0" encoding="utf-8"?>
<TreeNodes>
<Treenode CategoryID="1" CategoryName="基本设置" FatherID="0" IsChild="">
</Treenode>
<Treenode CategoryID="2" CategoryName="个人设置" FatherID="1">
</Treenode>
<Treenode CategoryID="3" CategoryName="部门代码设置" FatherID="1">
</Treenode>
<Treenode CategoryID="4" CategoryName="储位设置" FatherID="1">
</Treenode>
<Treenode CategoryID="5" CategoryName="请购作业" FatherID="5">
</Treenode>
<Treenode CategoryID="6" CategoryName="请购申请" FatherID="5">
</Treenode>
<Treenode CategoryID="7" CategoryName="请购查询" FatherID="5">
</Treenode>
</TreeNodes>

如上xml数据，怎样用javascript根据FatherID和CategoryID选数据?

[mrshelly]

Google XPath.

[rjzou2006]

var v = getElementsByTagName("Treenode");
if(v.CategoryID=="5")
{

}

[sweig0721]

var v = getElementsByTagName("Treenode");
怎样得到多少条记录？可以给个例子吗？