rem: if (!DNDUtils.checkCanDrop("OutlinerBuilder/column-add")) 
add: if (!DNDUtils.checkCanDrop("TreeBuilder/column-add")) 
context:   onDragOver: function(aEvent)  {    if (!DNDUtils.checkCanDrop("OutlinerBuilder/column-add"))      return;    var idx = this.getColumnIndexFromX(aEvent.clientX, 0.5);    this.mColumnInsertIndex = idx;    var col = this.getColumnAt(idx);        if (idx == -1)      this.markColumnInsert(col, "after");    else      this.markColumnInsert(col, "before");  },
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/d38a0937d9c93a0a9d913e2ac781e4328bb8cc73/inTreeBuilder.js/buggy/extensions/inspector/resources/content/jsutil/xul/inTreeBuilder.js