ruchi, if you had read my previous response to janovetz, you would have realised i had already conceded that point... i would also like to provide some friendly advice... read *all* the thread before providing friendly advice... cheers nik Nik Vogiatzis PhD Candidate: University of South Australia +++++++++++++++++++++++++++ Developing new generation Traffic Micro-simulation Tools for Traffic Engineers em: nikolaos.vogiatzis@unisa.edu.au