752   onHover: function(element, dropon, overlap) {  argument
753     if(Element.isParent(dropon, element)) return;
755     if(overlap > .33 && overlap < .66 && Sortable.options(dropon).tree) {
758       Sortable.mark(dropon, 'before');
759       if(dropon.previousSibling != element) {
762         dropon.parentNode.insertBefore(element, dropon);
763         if(dropon.parentNode!=oldParentNode)
765         Sortable.options(dropon.parentNode).onChange(element);
768       Sortable.mark(dropon, 'after');
769       var nextElement = dropon.nextSibling || null;
773         dropon.parentNode.insertBefore(element, nextElement);
774         if(dropon.parentNode!=oldParentNode)
776         Sortable.options(dropon.parentNode).onChange(element);
781   onEmptyHover: function(element, dropon, overlap) {  argument
783     var droponOptions = Sortable.options(dropon);
785     if(!Element.isParent(dropon, element)) {
788 …  var children = Sortable.findElements(dropon, {tag: droponOptions.tag, only: droponOptions.only});
792         var offset = Element.offsetSize(dropon, droponOptions.overlap) * (1.0 - overlap);
807       dropon.insertBefore(element, child);
818   mark: function(dropon, position) {  argument
820     var sortable = Sortable.options(dropon.parentNode);
829     var offsets = dropon.cumulativeOffset();
834         Sortable._marker.setStyle({left: (offsets[0]+dropon.clientWidth) + 'px'});
836         Sortable._marker.setStyle({top: (offsets[1]+dropon.clientHeight) + 'px'});