通过PHP连接Ftp

I have to connect to moteng site ftp. I have tried with below code but i'm not getting connected.

$ftp_server="ftp://dropbox.moteng.com/";
$ftp_user_name="xxxx";
$ftp_pass="xxxx";
$conn_id = ftp_connect($ftp_server);
$login_result = ftp_login($conn_id, $ftp_user_name, $ftp_pass);

Here login result is null.

But same login details working in browser.

Please help to complete this task. thanks

Directly from the manual:

The FTP server address. This parameter shouldn't have any trailing slashes and shouldn't be prefixed with ftp://.

You made both mistakes, having a trailing slash, and prefixing it with ftp://