how to set up automatic updates / plug-in installations

Everything works fine for me, but I can’t install plug-ins through the web interface neither the automatic upgrade works.

I tried with the regular FTP account information (which brings me to 3 levels up where the wordpress files are) a sub ftp account that brings to the directory that contains the wordpress folder (and the root files)

what am I doing wrong?

what sort of info should I put at the Account Information?

Is it about the permissions of the folders?

please help!