Ok you've found your problem the webroot for the default webserver is /var/www and is owned by root, which means since you login as webftp you can't write to the directories. You need to use the "chown" command and change the ownership to webftp in order to upload to /var/www, if you want webftp's home directory /home/webftp/<htdocs or public_html> to be webroot for the default site, then you need to change that in apache.
in order to change permissions with "chown" you'd do the following.
cd /var
chown -R webftp:webftp www
what this command does is change you to the /var directory, chown is the change ownership command, -R does it recursively meaning it changes the ownership in the directory you specify and any subdirectories. webftp:webftp is the owner:group that you want to own the directory and its contents.
Hope this helps.
Drew