JQuery Sortable and automatic scrolling

Question

I am trying to get JQuery Sortable to work but I have run into a slight usability problem.

The list that I am trying to sort is quite large (about 200 items). If the

Answer 1

Based on @marty 's answer, here is a fine tuned code that will: 1. Control speed of the scrolling 2. Will scroll down and scroll up without glitches. 3. Default speed is 7px at a time 4. movements of less than 7px will be ignored

var previousLocation, previousDelta;
    $( ".selector" ).sortable({
        sort: function(event, ui) {
            var currentScrollTop = $(window).scrollTop(),
                topHelper = ui.position.top,
                delta = topHelper - currentScrollTop;
            setTimeout(function() {
                if((delta < 7 && delta >=0) || (delta > -7 && delta <=0))
                    return;
                if(delta > 7){
                    delta = 7;
                    if((topHelper - previousDelta) < previousLocation){
                        delta = (delta * -1);
                    }
                }
                if(delta < -7){
                    delta = -7;
                    if((topHelper - previousDelta) > previousLocation){
                        delta = (delta * -1);
                    }
                }

                $(window).scrollTop(currentScrollTop + delta);
                previousLocation = topHelper; previousDelta = delta;
            }, 5);
        }
    });