function elementPosition(obj) {
        var curleft = 0, curtop = 0;
 
        if (obj.offsetParent) {
            curleft = obj.offsetLeft;
            curtop = obj.offsetTop;
 
            while (obj = obj.offsetParent) {
                curleft += obj.offsetLeft;
                curtop += obj.offsetTop;
            }
        }
 
        return { x: curleft, y: curtop };
    }
 
  function ScrollToControl(id)
        {
            var elem =  document.getElementById(id);
            var scrollPos = elementPosition(elem).y;
            scrollPos = scrollPos - document.documentElement.scrollTop;
            var remainder = scrollPos % 50;
            var repeatTimes = (scrollPos - remainder) / 50;
            ScrollSmoothly(scrollPos,repeatTimes);
            window.scrollBy(0,remainder);
        }
        var repeatCount = 0;
        var cTimeout;
        var timeoutIntervals = new Array();
 
        var timeoutIntervalSpeed;
        function ScrollSmoothly(scrollPos,repeatTimes)
        {
                if(repeatCount < repeatTimes)
                {
                window.scrollBy(0,50);
                }
                else
                {
                repeatCount = 0;
                clearTimeout(cTimeout);
                return;
                }
        repeatCount++;
        cTimeout = setTimeout("ScrollSmoothly('" + scrollPos + "','"+ repeatTimes +"')",10);
        }
 
example usage : 
ScrollToControl('elementID');
it moves to the control smoothly;