【XML】appendChild添加子节点

var myXML:XML =  
 <order> 
     <item id='1'> 
         <menuName>burger</menuName>  
         <price>3.95</price>   
    </item> 
     <item id='2'> 
         <menuName>fries</menuName>   
        <price>1.45</price>   
    </item> 
 </order>;
 
var newItem:XML =  
 <item id="3"> 
     <menuName>medium cola</menuName> 
    <price>1.25</price> 
 </item>;
 
 myXML.appendChild(newItem);
 
 trace(myXML);

//<order>
  <item id="1">
    <menuName>burger</menuName>
    <price>3.95</price>
  </item>
  <item id="2">
    <menuName>fries</menuName>
    <price>1.45</price>
  </item>
  <item id="3">
    <menuName>medium cola</menuName>
    <price>1.25</price>
  </item>
</order>