The PHP ftp_mkdir() function creates a new directory on the FTP server.

<?php
// connect and login to FTP server
$ftp_server = 'ftp.example.com';

$ftp_conn = ftp_connect($ftp_server) or die('Could not connect to ' . $ftp_server);
$login = ftp_login($ftp_conn, $ftp_username, $ftp_userpass);

$dir = 'javascript';

// create directory
if (ftp_mkdir($ftp_conn, $dir)) {
    echo 'Directory successfully created';
  }
else {
    echo 'Could not create directory';
}

// close connection
ftp_close($ftp_conn);
?>

// creates a new directory on the FTP server

ftp_mkdir(ftp_conn, dir)