SlideShowExtender on slide change

How to add an onchange event to the SlideShowExtender?

-After adding your SlideShowExtender, assign the image control to it and setting a BehaviorID

<cc1:SlideShowExtender BehaviorID="behaviorID" ID="SlideShowExtender1" runat="server" SlideShowServiceMethod="GetSlides" PlayInterval="5000" TargetControlID="imgScreen"  UseContextKey="True" AutoPlay="true" Loop="true"></cc1:SlideShowExtender>

-Add the following java script code inside your html code file:

<script language="javascript" type="text/javascript">  
    function pageLoad(){ 
        var slider1;  
        slider1 = $find("behaviorID"); 
        slider1.add_slideChanging(onSlideChanging);  
    }
     function onSlideChanging(sender, args){ 
        currentSlideIndex = args.get_slideIndex();  
        //Do what you want using this index
     }
</script>