用xml 读取省 市 县

<script   language="javascript"   type="text/javascript">
  //首先需要初始化
  var   xmlDoc;  
  var   nodeIndex;
  function   getxmlDoc()  
  {  
      xmlDoc=new   ActiveXObject("Microsoft.XMLDOM");  
          var   currNode;  
          xmlDoc.async=false;  
          xmlDoc.load("images/Area.xml");  
          if(xmlDoc.parseError.errorCode!=0)  
          {  
                  var   myErr=xmlDoc.parseError;  
                  alert("出错！"+myErr.reason);  
          }          
  }
  function Init()
  {
    //打开xlmdocm文档
    getxmlDoc();
    var   dropElement1=document.getElementById("country");
    var   dropElement2=document.getElementById("province");
    var   dropElement3=document.getElementById("city");  
    RemoveDropDownList(dropElement1);
    RemoveDropDownList(dropElement2);
    RemoveDropDownList(dropElement3);
    var  TopnodeList=xmlDoc.selectSingleNode("address").childNodes;
    if(TopnodeList.length>0)
    {
        //省份列表
        var country;
        var province;
        var city;
        for(var   i=0; i<TopnodeList.length;   i++)
        {
              //添加列表项目
              country=TopnodeList[i];      
              var   eOption=document.createElement("option");  
              eOption.value=country.getAttribute("name");
              eOption.text=country.getAttribute("name");
              dropElement1.add(eOption);
        }
        if(TopnodeList[0].childNodes.length>0)
        {
            //城市列表
            for(var i=0;i<TopnodeList[0].childNodes.length;i++)
            {
               var   id=dropElement1.options[0].value;
               //默认为第一个省份的城市
               province=TopnodeList[0];
               var   eOption=document.createElement("option"); 
               eOption.value=province.childNodes[i].getAttribute("name");  
               eOption.text=province.childNodes[i].getAttribute("name");  
               dropElement2.add(eOption);
            }
            if(TopnodeList[0].childNodes[0].childNodes.length>0)
            {
               //县列表
               for(var i=0;i<TopnodeList[0].childNodes[0].childNodes.length;i++)
               {
                  var   id=dropElement2.options[0].value;
                  //默认为第一个城市的第一个县列表
                  city=TopnodeList[0].childNodes[0]; 
                  var   eOption=document.createElement("option"); 
                  eOption.value=city.childNodes[i].getAttribute("name");  
                  eOption.text=city.childNodes[i].getAttribute("name");  
                  this.document.getElementById("city").add(eOption);
               }
            }
        }
    }
  }  
  function   selectCity()  
  {       var   dropElement1=document.getElementById("country");
          var   name=dropElement1.options[dropElement1.selectedIndex].value;
          //alert(id);
          var   countryNodes=xmlDoc.selectSingleNode('//address/province [@name="'+name+'"]');  
          //alert(countryNodes.childNodes.length);
          var   province=document.getElementById("province");      
          var   city=document.getElementById("city");      
          RemoveDropDownList(province);  
          RemoveDropDownList(city);
          if(countryNodes.childNodes.length>0)
          {
               //填充城市         
               for(var   i=0;   i<countryNodes.childNodes.length;   i++)  
               {  
                  var   provinceNode=countryNodes.childNodes[i];    
                  var   eOption=document.createElement("option");  
                  eOption.value=provinceNode.getAttribute("name");  
                  eOption.text=provinceNode.getAttribute("name");  
                  province.add(eOption);  
               }
               if(countryNodes.childNodes[0].childNodes.length>0)
               {
                  //填充选择省份的第一个城市的县列表
                  for(var i=0;i<countryNodes.childNodes[0].childNodes.length;i++)
                  {
                      //alert("i="+i+"\r\n"+"length="+countryNodes.childNodes[0].childNodes.length+"\r\n");
                      var   dropElement2=document.getElementById("province");
                      var   dropElement3=document.getElementById("city");
                      //取当天省份下第一个城市列表
                      var cityNode=countryNodes.childNodes[0];
                      //alert(cityNode.childNodes.length);
                      var   eOption=document.createElement("option"); 
                      eOption.value=cityNode.childNodes[i].getAttribute("name");  
                      eOption.text=cityNode.childNodes[i].getAttribute("name");  
                      dropElement3.add(eOption);
                  }
               }
          }
  }  
  function   selectCountry()  
  {  
          var   dropElement2=document.getElementById("province");  
          var   name=dropElement2.options[dropElement2.selectedIndex].value;  
          var   provinceNode=xmlDoc.selectSingleNode('//address/province/city[@name="'+name+'"]');  
          var   city=document.getElementById("city");      
          RemoveDropDownList(city);  
          for(var   i=0;   i<provinceNode.childNodes.length;   i++)  
          {  
                  var   cityNode=provinceNode.childNodes[i];    
                  var   eOption=document.createElement("option");  
                  eOption.value=cityNode.getAttribute("name");  
                  eOption.text=cityNode.getAttribute("name");  
                  city.add(eOption);  
          }  
  }  
  function   RemoveDropDownList(obj)  
  {  
      if(obj)
      {
          var   len=obj.options.length;  
          if(len>0)
          {
            //alert(len);  
            for(var   i=len;i>=0;i--)  
            {  
                  obj.remove(i);  
            }
          }
       }
           
  }
</script>

<select id="country" name="country" runat="server" onChange="selectCity();">
<option value="" selected="true">省/直辖市</option>
</select>&nbsp;
<select id="province" name="province" runat="server" onChange="selectCountry()">
<option value="" selected="true">请选择</option>
</select>&nbsp;
<select id="city" name="city" runat="server" >
<option value="" selected="true">请选择</option>
</select>



省市区回填会比较慢

<script type="text/JavaScript">
  //首先需要初始化
  var   xmlDoc;  
  var   nodeIndex;
  function   getxmlDoc()  
  {  
      xmlDoc=new   ActiveXObject("Microsoft.XMLDOM");  
          var   currNode;  
          xmlDoc.async=false;  
          xmlDoc.load("<%=path%>/images/Area.xml");  
          if(xmlDoc.parseError.errorCode!=0)  
          {  
                  var   myErr=xmlDoc.parseError;  
                  alert("出错！"+myErr.reason);  
          }          
  }
  function Init1()
  {
    //打开xlmdocm文档
    getxmlDoc();
    var   dropElement1=document.getElementById("country");
    var   dropElement2=document.getElementById("province");
    var   dropElement3=document.getElementById("city");  
    RemoveDropDownList(dropElement1);
    RemoveDropDownList(dropElement2);
    RemoveDropDownList(dropElement3);
    var  TopnodeList=xmlDoc.selectSingleNode("address").childNodes;
    if(TopnodeList.length>0)
    {
        //省份列表
        var country;
        var province;
        var city;
        for(var   i=0; i<TopnodeList.length;   i++)
        {
              //添加列表项目
              country=TopnodeList[i];      
              var   eOption=document.createElement("option");  
              eOption.value=country.getAttribute("name");
              eOption.text=country.getAttribute("name");
              dropElement1.add(eOption);
       
        if(TopnodeList[i].childNodes.length>0)
        {
            //城市列表
            for(var j=0;j<TopnodeList[i].childNodes.length;j++)
            {
               var   id=dropElement1.options[i].value;
               //默认为第一个省份的城市
               province=TopnodeList[i];
               var   eOption=document.createElement("option"); 
               eOption.value=province.childNodes[j].getAttribute("name");  
               eOption.text=province.childNodes[j].getAttribute("name");  
               dropElement2.add(eOption);
                if(TopnodeList[i].childNodes[j].childNodes.length>0)
            {
               //县列表
               for(var k=0;k<TopnodeList[i].childNodes[j].childNodes.length;k++)
               {
                //  var   id=dropElement2.options[k].value;
                  //默认为第一个城市的第一个县列表
                  city=TopnodeList[i].childNodes[j]; 
                  var   eOption=document.createElement("option"); 
                  eOption.value=city.childNodes[k].getAttribute("name");  
                  eOption.text=city.childNodes[k].getAttribute("name");  
                  this.document.getElementById("city").add(eOption);
               }
            }
            }
          
        }
       
       }
    }
  }  
  function   selectCity()  
  {       var   dropElement1=document.getElementById("country");
          var   name=dropElement1.options[dropElement1.selectedIndex].value;
          //alert(id);
          var   countryNodes=xmlDoc.selectSingleNode('//address/province [@name="'+name+'"]');  
          //alert(countryNodes.childNodes.length);
          var   province=document.getElementById("province");      
          var   city=document.getElementById("city");      
          RemoveDropDownList(province);  
          RemoveDropDownList(city);
          if(countryNodes.childNodes.length>0)
          {
               //填充城市         
               for(var   i=0;   i<countryNodes.childNodes.length;   i++)  
               {  
                  var   provinceNode=countryNodes.childNodes[i];    
                  var   eOption=document.createElement("option");  
                  eOption.value=provinceNode.getAttribute("name");  
                  eOption.text=provinceNode.getAttribute("name");  
                  province.add(eOption);  
               }
               if(countryNodes.childNodes[0].childNodes.length>0)
               {
                  //填充选择省份的第一个城市的县列表
                  for(var i=0;i<countryNodes.childNodes[0].childNodes.length;i++)
                  {
                      //alert("i="+i+"\r\n"+"length="+countryNodes.childNodes[0].childNodes.length+"\r\n");
                      var   dropElement2=document.getElementById("province");
                      var   dropElement3=document.getElementById("city");
                      //取当天省份下第一个城市列表
                      var cityNode=countryNodes.childNodes[0];
                      //alert(cityNode.childNodes.length);
                      var   eOption=document.createElement("option"); 
                      eOption.value=cityNode.childNodes[i].getAttribute("name");  
                      eOption.text=cityNode.childNodes[i].getAttribute("name");  
                      dropElement3.add(eOption);
                  }
               }
          }
  }  
  function   selectCountry()  
  {  
          var   dropElement2=document.getElementById("province");  
          var   name=dropElement2.options[dropElement2.selectedIndex].value;  
          var   provinceNode=xmlDoc.selectSingleNode('//address/province/city[@name="'+name+'"]');  
          var   city=document.getElementById("city");      
          RemoveDropDownList(city);  
          for(var   i=0;   i<provinceNode.childNodes.length;   i++)  
          {  
                  var   cityNode=provinceNode.childNodes[i];    
                  var   eOption=document.createElement("option");  
                  eOption.value=cityNode.getAttribute("name");  
                  eOption.text=cityNode.getAttribute("name");  
                  city.add(eOption);  
          }  
  }  
  function   RemoveDropDownList(obj)  
  {  
      if(obj)
      {
          var   len=obj.options.length;  
          if(len>0)
          {
            //alert(len);  
            for(var   i=len;i>=0;i--)  
            {  
                  obj.remove(i);  
            }
          }
       }
           
  }
</script>