Changes the directory on the FTP server you are logged in. The parameter can either be an absolute path (e.g. '/home/mydir') or a relative one (e.g. 'mydir').
string $directory - The directory you want to change to. This can either be an absolute path (e.g. '/home/mydir') or a relative one (e.g. 'mydir').
The returned PEAR_Error object in case of an error is unspecific. You can ignore the errornumber and errormessage, because only "Directory change failed" will be returned if the operation fails.