rem: while ((parentRecord = parentRecord.parentRecord)) ++rv; 
add: while ("parentRecord" in parentRecord && (parentRecord = parentRecord.parentRecord)) ++rv; 
context: function tovr_getLevel (){    var rv = 0;    var parentRecord = this.parentRecord;    while ((parentRecord = parentRecord.parentRecord)) ++rv;    return rv;}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/e711edc14f9f9f43c8fc7d007226dcc5ca78ab65/tree-utils.js/clean/extensions/venkman/resources/content/tree-utils.js