[flexcoders] DataTipRenderer Problem

[RS Tanvir]

Hello,

im facing a problem regarding DataTipRenderer of a chart.

in the application i have two button and one chart.
when i clicked one of the button it will set the dataTipRenderer of the chart 
to a certain DataTip and when i will click the other button it will set the 
dataTipRenderer to another DataTip class.

The problem is, it's not switching. :((
it always remains in the initial stage. :((

here is the code:

<?xml version="1.0"?>
<!-- charts/CustomDataTipRenderer.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"; 
creationComplete="applyCustomDataTips()">
  <mx:Script><![CDATA[
        import mx.charts.chartClasses.DataTip;
        import mx.skins.halo.ToolTipBorder;
        import mx.skins.Border;
        import mx.skins.RectangularBorder;
        import mx.skins.ProgrammaticSkin;
     import mx.collections.ArrayCollection;
     
     [Bindable]
     public var expenses:ArrayCollection = new ArrayCollection([
        {Month:"Jan", Profit:2000, Expenses:1500},
        {Month:"Feb", Profit:1000, Expenses:200},
        {Month:"Mar", Profit:1500, Expenses:500}
     ]);
    private function applyCustomDataTips():void {
       // myChart.setStyle("dataTipRenderer",mx.skins.ProgrammaticSkin);
        
    }
    
    private function toolTipOn():void
    {
        myChart.setStyle("dataTipRenderer",DataTip);
    }
    
    private function toolTipOff():void
    {
        myChart.setStyle("dataTipRenderer",mx.skins.ProgrammaticSkin);
    }
    
  ]]></mx:Script>
  
  <mx:HBox width="100%" height="10%">
  <mx:Button label="Tool Tip On" click="toolTipOn()"/>
  <mx:Button label="Tool Tip Off" click="toolTipOff()"/>
  </mx:HBox>
  <mx:Panel title="Bar Chart">
     <mx:BarChart id="myChart" 
        dataProvider="{expenses}" 
        showDataTips="true"
     >
        <mx:verticalAxis>
           <mx:CategoryAxis 
                dataProvider="{expenses}" 
                categoryField="Month"
           />
        </mx:verticalAxis>
        <mx:series>
           <mx:BarSeries 
                    id="bar1"
                yField="Month" 
                xField="Profit"
                displayName="Profit"
           />
           <mx:BarSeries 
                        id="bar2"
                yField="Month" 
                xField="Expenses"
                displayName="Expenses"
           />
        </mx:series>
     </mx:BarChart>
     <mx:Legend dataProvider="{myChart}"/>
  </mx:Panel>
</mx:Application>