Dynamically Change Fusion Chart Value with Slider Event in flex

Question

I am having a set of slider for each bar in the graph. I have bindded all the sliders with their corresponding bars. When i change the value of slider the value in the ArrayCollection changes and i have also used

singleData.refresh();

but the values in the chart remains unchanged. How can i update the values in the chart with the change in values of the slider.

Here is my code:

<mx:Script>
    <![CDATA[
        import mx.events.SliderEvent;
        import mx.collections.ArrayCollection;

        [Bindable]
        private var singleData:ArrayCollection=new ArrayCollection([
               {label:'Diego', value:'22'},
               {label:'Steve', value:'20'},
        ]);

        private function updateChart(event:SliderEvent, index:Number):void{
            singleData.getItemAt(index).value = String(event.value);
            singleData.refresh();
        } 
    ]]>
</mx:Script>


<ns1:FusionCharts x="10" y="10" FCChartType="Column3D" width="500">  
    <ns1:FCChartData  FCParams="{chartParam}" FCData="{singleData}" />
</ns1:FusionCharts>

<mx:VBox x="10" y="318">
    <mx:HBox>
        <mx:Label text="Diego:" width="100"/>
        <mx:HSlider id="SliderDiego" change="{updateChart(event,0)}" liveDragging="true" value="{singleData.getItemAt(0).value}" minimum="0" maximum="100" width="120"/>                    
    </mx:HBox>
    <mx:HBox>
        <mx:Label text="Steve:" width="100"/>
        <mx:HSlider id="SliderSteve" change="{updateChart(event,1)}" liveDragging="true" value="{singleData.getItemAt(1).value}" minimum="0" maximum="100" width="120"/>                    
    </mx:HBox>
</mx:VBox>