Any idea why this works for dataGrid but not for a list?

Question

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
      xmlns:s="library://ns.adobe.com/flex/spark"
      xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" xmlns:deviceservice="services.deviceservice.*">
<fx:Script>
  <![CDATA[
   import mx.collections.ArrayCollection;
   import mx.controls.Alert;
   import mx.events.DragEvent;
   import mx.events.FlexEvent;
   import spark.events.IndexChangeEvent;
   //[Bindable]public var totalPrice:int =0;
   private function initApp():void {
    firstList.dataProvider = new ArrayCollection([
     {label:"First", data:"1",value:"first"},
     {label:"Second", data:"2",value:"second"},
     {label:"Third", data:"3",value:"third"},
     {label:"Fourth", data:"4",value:"fourth"}
    secondList.dataProvider = new ArrayCollection([]);
   protected function initbut_clickHandler(event:MouseEvent):void
    initApp();
   protected function popupbut_clickHandler(event:MouseEvent):void
    //totalPrice+=int( secondList.selectedItem.data);
    //Alert.show(" The total price is:"+totalPrice );
   protected function secondList_dragDropHandler(event:DragEvent):void
    var artistList:String="";
  var dragObj:Array=
     event.dragSource.dataForFormat("items") as Array;
    trace (dragObj[0].value);
    artistList="Data: " + dragObj[0].value;
    Alert.show(""+artistList);               
   protected function firstList_creationCompleteHandler(event:FlexEvent):void
    initApp();
  ]]>
</fx:Script>
<s:List x="73" y="106" width="125" id="firstList"  dragEnabled="true"
    dragMoveEnabled="true" dropEnabled="true"  allowMultipleSelection="true" creationComplete="firstList_creationCompleteHandler(event)" ></s:List>
<s:List x="409" y="106" width="162" id="secondList"
   dropEnabled="true" dragEnabled="true"
   dragMoveEnabled="true"
    dragDrop="secondList_dragDropHandler(event)" ></s:List>
<s:Button x="187" y="245" label="Init app" id="initbut" click="initbut_clickHandler(event)"/>
<mx:PopUpButton x="359" y="266" label="PopUpButton" id="popupbut"  click="popupbut_clickHandler(event)"/>
<s:Label x="631" y="165" text="Label" height="17" id="show1"/>
</s:Application>

Answer 1

the example is shown here for a dataGrid:
http://livedocs.adobe.com/flex/3/html/help.html?content=dragdrop_5.html
It's the example located at the bottom:
I tried using a form instead of a dataGrid but it does not work, especially for the one in bold.