TF-IDF Calculation - Normalization

Joyo

Hi @ all,
I am trying to reproduce some TF-IDF calculations, which I ran with RapidMiner. Unfortunately I can't get the right results.
According to http://rapid-i.com/rapidforum/index.php?action=printpage;topic=3728.0 the TF-IDF score is "normalized". Can someone provide a detailed example, how this normalization is done?
Thanks in advance :-)