jquery 通过xpath提出节点问题

Question

有引用以下js
  <script src="jquery-1.7.2.min.js" type="text/javascript"></script>
   <script src="jquery.js" type="text/javascript"></script>  var xmlstr="<?xml version='1.0' encoding='UTF-8'?>"+
            "<CityTb>" +
"<Rows>" +
"<id>378</id>" +
"<Lab>澳门</Lab>" +
"<PY>AM</PY>" +
"<Pid>90</Pid>" +
"</Rows>" +
"<Rows>" +
"<id>1</id>" +
"<Lab>中国</Lab>" +
"<PY>ZG</PY>" +
"<Pid>0</Pid>" +
"</Rows>" +
"<Rows>" +
"<id>2</id>" +
"<Lab>福建</Lab>" +
"<PY>FJ</PY>" +
"<Pid>1</Pid>" +
"</Rows>" +
"<Rows>" +
"<id>3</id>" +
"<Lab>厦门</Lab>" +
"<PY>XM\</PY>" +
"<Pid>2</Pid>" +
"</Rows>" +
"<Rows>" +
"<id>12</id>" +
"<Lab>北京</Lab>" +
"<PY>BJ</PY>" +
"<Pid>1</Pid>" +
"</Rows>"+
"</CityTb>";    var xmdoc=$.parseXML(xmlstr);
   var xmle = $(xmdoc).find('Rows[Pid=1]');
   alert(xmle.length);Rows[Pid=1] 这个xpath 在一第三方在线测试xpath网站测试没问题，但这里为什么 显示为没有找到了 
显示xmle.length =0   搞了老久没有搞定，特请高手指点