"Fatal error" upon transfer

Fatal error: Call to undefined function ftp_connect() in /customers/6/1/e/fotodoktoren.com/httpd.www/wp-content/plugins/easy-ftp-upload/Easy_FTP_Upload.php on line 154

I get this error code when I try to transfer a file.
Any idea what’s wrong?

http://wordpress.org/extend/plugins/easy-ftp-upload/