Hi, all. This mail has nothing to do with R . But as a Chinese, I feel responsible to send this mail. :) The 2008 Beijing Olympics is beginning , welcome to Beijing ! best regards ! ----------------------------------------------- Peng Jiang ?? ,Ph.D. Candidate Antai College of Economics & Management ???????? Department of Mathematics ??? Shanghai Jiaotong University (Minhang Campus) 800 Dongchuan Road 200240 Shanghai P. R. China