rem: new Effect.MoveBy(element, -top_offset, -left_offset, {duration:dur}); 
add: element._revert = new Effect.MoveBy(element, -top_offset, -left_offset, {duration:dur}); 
context:       reverteffect: function(element, top_offset, left_offset) {        var dur = Math.sqrt(Math.abs(top_offset^2)+Math.abs(left_offset^2))*0.02;        new Effect.MoveBy(element, -top_offset, -left_offset, {duration:dur});      },
meta: 3991	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/3991/d29159eae8749c508d01bb447868321a3ba6bbfa/dragdrop.js/buggy/manager/media/script/scriptaculous/dragdrop.js