Export bookmarks as csv file

I have a script which exports bookmarks to a csv file.

The script actually works to a stage where the csv file is created and opened with the last book mark name being listed in the csv file.

All of the other bookmark names are not listed.

Some advise would be most appreciated in modifying the script to list all of the bookmarks in the csv file.

var bm = this.bookmarkRoot;

var ibmLength = bm.children.length;

for (var i = 0; i < ibmLength; i++)

var bookname = bm.children.name;

var fieldValues = [];

fieldValues.push(bookname);

this.createDataObject('output.csv', fieldValues.join());

this.exportDataObject({ cName:'output.csv', nLaunch:'2'});

thank you