怎么检索XML

如何检索XML？
<?xml   version= "1.0 "   encoding= "GB2312 "?>
<contact>    
<person>
        <name> xyz </name>
        <number> 333 </number>
        <email> ert </email>
    </person>
</contact>
我想通过输入xyz检索并确定节点，请问该怎么做？

[解决办法]
try..

XmlDocument doc = new XmlDocument();
doc.Load(@ "../../test.xml ");
string itemname = "xyz ";
XmlNodeList nodes = doc.SelectNodes(@ "//*[text()= ' "+itemname + " '] ");
foreach (XmlNode node in nodes)
{
Console.WriteLine(node.Name);
}

[解决办法]
itemname＝ 'xyz '
要有引号的
string itemname = "xyz ";
XmlNodeList nodes = doc.SelectNodes(@ "//*[text()= ' "+itemname + " '] ");