loading a another website into smart ftp

I am not sure how to upload another website into my smart ftp. I already have one uploaded in it and I'm not sure if I need to choose a totally different id and password that will be associated with the new one or not. Any help from someone who has multiple sites uploaded in Smart ftp would be greatly appreciated.

Normally all I did was just delete the info already in therre and type in the new info; it would automatically create a tab with that site, and still leave my other server open. However, the newest version seems to be having issues with that...