请教一下用JS遍历子节点的有关问题

请问一下用JS遍历子节点的问题
<bookstore>
<book   category= "WEB ">
    <title   lang= "en "> XQuery   Kick   Start </title>  
    <author> James   McGovern </author>    
    <year> 2003 </year>  
    <price> 49.99 </price>  
</book>
<book   category= "WEB ">
    <title   lang= "en "> Learning   XML </title>  
    <author> Erik   T.   Ray </author>  
    <year> 2003 </year>  
    <price> 39.95 </price>  
</book>
</bookstore>

如果我现在用
var   x=xmlDoc.getElementsByTagName( "book ");
定义以后该怎么样获得所有子节点呢?

for(i=0;i <x.length;i++)
{
alert(x[i].childNodes[0].childNodes[0]nodeValue);
}
我现在是这样写的，但是不行

可以假设的是book下的子节点的Name都是不可知的

[解决办法]
<script language= "javascript ">
var xmlDom=new ActiveXObject( "MSXML2.DOMDocument.3.0 ");
xmlDom.async= "false ";
xmlDom.load( "test.xml ");
var x=xmlDom.getElementsByTagName( "book ");
for(var i=0;i <x.length;i++)
{
document.write( "|&nbsp;&nbsp;&nbsp;+-- "+x.item(i).nodeName+ " <br/> ");
if(x.item(i).hasChildNodes)
{
xmlSubNode=x.item(i).childNodes;
for(var j=0;j <xmlSubNode.length;j++)
{
document.write( "|&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp;&nbsp;+-- ");
document.write(xmlSubNode.item(j).nodeName+ ": ");
document.write(xmlSubNode.item(j).text+ " <br/> ");
}
}
}
</script>
测试通过！
[解决办法]
var x=xmlDom.getElementsByTagName( "book ");
for(var i=0;i <x.length;i++)
{
document.write( "|&nbsp;&nbsp;&nbsp;+-- "+x.item(i).nodeName+ " <br/> ");
if(x.item(i).hasChildNodes)
{

xmlSubNode=x.item(i).childNodes;
for(var j=0;j <xmlSubNode.length;j++)
{
if(xmlSubNode.item(j).nodeType!=1) continue; //*不是element的过滤掉
document.write( "|&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp;&nbsp;+-- ");
document.write(xmlSubNode.item(j).nodeName+ ": ");
if (window.ActiveXObject)
document.write(xmlSubNode.item(j).text+ " <br/> ");
else
document.write(xmlSubNode.item(j).textContent+ " <br/> ");
}
}
}