急？？？ C# 读xml
xml   结构如下
<?xml   version= "1.0 "   encoding= "utf-8 "   ?>  
<class_three>
      <type   id= "1 "   class_id= "1 "   class_name= "耳   环 "> </type>
      <type   id= "2 "   class_id= "1 "   class_name= "发   夹 "> </type>
      <type   id= "3 "   class_id= "1 "   class_name= "BB   夹 "> </type>
      <type   id= "4 "   class_id= "1 "   class_name= "一字夹 "> </type>
      <type   id= "5 "   class_id= "1 "   class_name= "发   圈 "> </type>
      <type   id= "6 "   class_id= "1 "   class_name= "牛角夹 "> </type>
      <type   id= "7 "   class_id= "1 "   class_name= "青蛙夹 "> </type>
      <type   id= "8 "   class_id= "1 "   class_name= "头   箍 "> </type>
      <type   id= "9 "   class_id= "2 "   class_name= "项链、项坠 "> </type>
      <type   id= "10 "   class_id= "2 "   class_name= "戒指、指环 "> </type>
      <type   id= "11 "   class_id= "2 "   class_name= "手镯、手链 "> </type>
      <type   id= "12 "   class_id= "2 "   class_name= "挂件、佩饰 "> </type>
      <type   id= "13 "   class_id= "3 "   class_name= "手机挂件 "> </type>
      <type   id= "14 "   class_id= "3 "   class_name= "人造水晶 "> </type>
      <type   id= "15 "   class_id= "3 "   class_name= "天然制品 "> </type>
      <type   id= "16 "   class_id= "4 "   class_name= "项链、项坠 "> </type>
      <type   id= "17 "   class_id= "4 "   class_name= "戒指、指环 "> </type>
      <type   id= "18 "   class_id= "5 "   class_name= "戒指/项坠 "> </type>
      <type   id= "19 "   class_id= "5 "   class_name= "耳饰 "> </type>
      <type   id= "20 "   class_id= "5 "   class_name= "手链/手镯 "> </type>
      <type   id= "21 "   class_id= "5 "   class_name= "挂件/吊饰 "> </type>
      <type   id= "22 "   class_id= "5 "   class_name= "戒指 "> </type>
</class_three>

怎么读取   class_id=1   的节点，并放到   dataset   中啊  
谢谢！！

------解决方案--------------------
选用DataSet.ReadXml 方法方法把数据都取出来,然后用DataTable的Select方法选出class_id==1的记录就是了.