Vsftpd - making login users

i have vsFTPD (very secure FTP daemon) on CentOS with Webmin Control Panel. i made a user called ftp and set a password for it. and put it in a group ftpusers. its home directory is /vars/html.

so i turn on the FTP server. and i login with a client into the ftp username and password. and it goes to the directory that i appointed as expected. but the thing is it wont upload or delete files, but it can browse (i didnt try to download files yet).

i can't figure out where to change the settings so the user can upload and delete files etc (i think i remeber reading somewhere it might be related to CHMOD values or something but i dont know anything about that)