Dear prof: I have received your answer,thank you very much! I'll try it ,if i still can not use it ,i will post it to you! Yours sincerely! yuzhiguo -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20071124/a8ab38e5/attachment.html>