Returns TRUE if the
file specified by filename
exists; FALSE otherwise.
This function will not work on remote files; the file to be
examined must be accessible via the server's filesystem.
The results of this function are cached. See
clearstatcache() for more details.
Using Windows shares: On windows, use //computername/share/filename or \\\\computername\share\filename to check files on network shares.
See also is_readable(),
is_writable(), is_file() and file().