Attempts to create the directory specified by pathname.
Note that you probably want to specify the mode as an octal number, which means it should have a leading zero. The mode is also modified by the current umask, which you can change using umask().
Note: Mode is ignored on Windows, and became optional in PHP 4.2.0.
The mode is 0777 by default, which means the widest possible access. For more information on modes, read the details on the chmod() page.
Returns TRUE on success or FALSE on failure.
See also rmdir().