Get Layer By ComboBox

weiwang3

want to be able to turn on and off the layer (visibleLayers) by ComboBox. I'm attempting to create three ComboBoxs for the user to toggle the visibility of layers in a dynamic map service layer. these three ComboxBoxs Respectively represent "dynamic services", "Year", "Month" .
I know There are some mistakes the code , but I can not modify,Please help me.
I referred to the http://forums.arcgis.com/threads/2106-Radio-Button-on-off-Layers?highlight=Dynamic+layers

Here's One of them my relevant MapServer:

http://219.246.47.247/ArcGIS/rest/se...day5/MapServer


Service Description:

Map Name: Layers

All Layers and Tables

Layers:


xianjie (0)
ma021011 (1)
ma021021 (2)
ma031101 (3)
ma061215 (4)
ma061215 (5)

eg."ma021011": "ma" representative "Lable"; "02" representative "Year(2002)"; "10" representative "month"; "11" representative "day"

my relevant mxml:

<?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" 
xmlns:esri="http://www.esri.com/2008/ags"
minWidth="955" minHeight="600">
<s:layout>
<s:VerticalLayout/>
</s:layout>
<fx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.controls.RadioButton;
import mx.events.ItemClickEvent;

private function loadLayerName():void
{
layerPanel.removeAllChildren();

//loop through each layer and add as a radiobutton
var aa:String = "ma" + yearURL.selectedItem.toString() + monthURL.selectedItem.toString();


for(var i:uint = 0; i < (dynamicLayer.layerInfos.length); i++) 
{

if (aa = dynamicLayer.layerInfos.name);
{

var radioBtn:RadioButton = new RadioButton;
radioBtn.groupName = "radioBtnGroup";
radioBtn.value = i;
radioBtn.label = dynamicLayer.layerInfos.name;
layerPanel.addChild(radioBtn);
}
}

//set the visible layer the first radio button
radioBtnGroup.selectedValue = 0;
dynamicLayer.visibleLayers = new ArrayCollection([0]);
}

private function radioClickHandler(event:ItemClickEvent):void
{
// update the visible layers to only show the layer selected
dynamicLayer.visibleLayers = new ArrayCollection([event.index]);

} 
]]>
</fx:Script>
<fxeclarations>
<!--  -->
</fxeclarations>

<esri:Map id="myMap">

<esri:ArcGISDynamicMapServiceLayer id="dynamicLayer"
load="loadLayerName()"
url="http://219.246.47.247/ArcGIS/rest/services/{myURL.selectedItem}/MapServer" />
</esri:Map>

<mx:ComboBox id="myURL" selectedIndex="0" horizontalCenter="0">
<fx:Array>

<fx:String>day</fx:String>
<fx:String>day5</fx:String>
<fx:String>day10</fx:String>
</fx:Array>

</mx:ComboBox>

<mx:ComboBox id="yearURL">
<fx:Array>

<fx:String>2002</fx:String>
<fx:String>2003</fx:String>
<fx:String>2006</fx:String>
</fx:Array>

</mx:ComboBox>

<mx:ComboBox id="monthURL">
<fx:Array>

<fx:String>10</fx:String>
<fx:String>11</fx:String>
<fx:String>12</fx:String>
<fx:String>01</fx:String>
<fx:String>02</fx:String>
<fx:String>03</fx:String>
</fx:Array>

</mx:ComboBox>

<mx:Panel id="layerPanel" width="300" height="250" x="20" y="250" paddingLeft="20">
<mx:RadioButtonGroup id="radioBtnGroup" itemClick="radioClickHandler(event)"/>
</mx:Panel>

</s:Application>