rem: var kids = this.mColGroup.childNodes; 
add: var kids = this.mColGroup.childNodes; 
context:   onDragOver: function(aEvent)  {    if (!DNDUtils.checkCanDrop("TreeTableBuilder/column-add"))      return;          var idx = this.getColumnIndexFromX(aEvent.clientX, 50);    this.mColumnInsertIndex = idx;    var kids = this.mColGroup.childNodes;     var col = this.getColumnAt(idx);    if (idx == -1)      this.markColumnInsert(col, "after", idx);    else      this.markColumnInsert(col, "before", idx);  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/0b2dd2b2d2fd037df917e07645fa019a963332a5/inTreeTableBuilder.js/clean/extensions/inspector/resources/content/jsutil/xul/inTreeTableBuilder.js