初学者求一段xpath如何写啊

菜鸟求一段xpath怎么写啊?
<?xml version="1.0" encoding="gb2312" ?> 
<root>
  <layers>
  <layer>
  <layername>集体食堂</layername> 
  <Editable>true</Editable> 
  <Table>集体食堂</Table> 
  <Related>true</Related> 
  <RelationTable>集体食堂_属性</RelationTable> 
  <showField>申请单位</showField> 
  <RelationField>许可证号</RelationField> 
  <RelatedField>许可证号</RelatedField> 
  </layer>
  <layer>
  <layername>门牌</layername> 
  <Editable>true</Editable> 
  <Table>门牌</Table> 
  <Related>true</Related> 
  <RelationTable>门牌_属性</RelationTable> 
  <showField>门牌号</showField> 
  <RelationField>门牌号</RelationField> 
  <RelatedField>门牌号</RelatedField> 
  </layer>
  </layers>
  </root>

问我如何求得 editalble 为TRUE的 layer节点列表.

并且我获得这个节点nodeslist 如何取得每个节点的子节点的layername的值呢?

[解决办法]

VBScript code

<%set parser=Server.CreateObject("MSXML2.DOMDocument")parser.async=falseparser.load(Server.MapPath("1.xml"))if parser.parseError.errorCode<>0 then               s="Error on line "&parser.parseError.Line&vbCrLf               s=s&parser.parseError.srcText &vbCrLf               s=s&Space(parser.parseError.linepos)               s=s&"---"&parser.parseError.reason               MsgBox send ifset strE=parser.selectNodes("//layer/Editable[.='true']") if Not strE is Nothing then        for i=0 to strE.length-1                set layE=strE.item(i).previousSibling              Response.Write layE.firstChild.nodeValue&"<br/>"        next end if %>
[解决办法]
可以参考一下这篇：http://blog.csdn.net/cds27/archive/2008/04/18/2305166.aspx
[解决办法]
HTML code
<?xml version="1.0" encoding="utf-8"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"    xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">  <xsl:output method="html" indent="yes"/>  <xsl:template match="//root">    <xsl:for-each select ="//layer[Editable='true ']">      <xsl:value-of select ="layername"/>    </xsl:for-each>  </xsl:template></xsl:stylesheet>
[解决办法]
//layer[Editable="true"]