var timesClicked = 0;

    function OnClientItemClickedHandler(sender, eventArgs)
    {       
        // alert(eventArgs.Item.Text + '__1__' + timesClicked);
        if(sender.ExpandedItem != null)
        {            
            if(sender.ExpandedItem == sender.SelectedItem)
            {
                // alert(eventArgs.Item.Text + '__2__' + timesClicked);
                if(timesClicked == 0){
                sender.ExpandedItem.Collapse();};
            }
        };
    }
    
    function OnClientItemExpandHandler(sender, eventArgs)
    {
        timesClicked = 1;
    }
    
    function OnClientItemCollapseHandler(sender, eventArgs)
    {
        timesClicked = 0;
    }
    
    function OnClientItemClickingHandler(sender, eventArgs)
    {
        if(sender.SelectedItem==sender.FocusedItem || sender.FocusedItem==null)
        {
            if(timesClicked == 0) { timesClicked = 1 }
            else { timesClicked = 0 };   
        };
    }