rem: if(Sortable._marker) Element.hide(Sortable._marker); 
add: if(Sortable._marker) Sortable._marker.hide(); 
context:   unmark: function() {    if(Sortable._marker) Element.hide(Sortable._marker);  },
meta: 6359	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/6359/52d313976f72b3f30c833a7675d476a595bc284d/dragdrop.js/buggy/web/js/dragdrop.js