controlling timeline with touch

hey all

I have animation timeline controled by the mousewheel,

here is the code i use -

composition ready-

$(window).bind('mousewheel', function(event) {

            var diro = event.originalEvent.wheelDelta < 0 ? 'Up' : 'Down';

            var velo = Math.abs(event.originalEvent.wheelDelta);

            $(this).text(diro + ' at a velocity of ' + velo);

            if(diro == 'Up')

            sym.play();

            else

            sym.playReverse();

        });

the problem is on touch screen....

what should i do to make this work on touch screen as well on mouse use?

many tnx