rem: var headers = this.mOutliner.getElementsByTagName("outlinercol"); 
add: var headers = this.mTree.getElementsByTagName("treecol"); 
context:   getColumnIndexFromHeader: function(aHeader)  {    var headers = this.mOutliner.getElementsByTagName("outlinercol");    for (var i = 0; i < headers.length; ++i) {      if (headers[i] == aHeader)        return i;    }    return -1;  },
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