how to display a file's last updated time using php?

Hi, friends, I want to display the last updated time of a file using php, but I don't know which function I should use. It seems that the date() just show the current time. For html file, a simple javascript works well, but in php files that script works weired. How to solve that problem? Thanks a lot. _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com