Trouble with mesh after subsurf

The image will explaim my problem. I’ve created this bottle using ‘extrude’. After subsurf i’ve noticed that two faces were ‘untouched’ by subsurf in the bottom. And after shift+e is the result in neck area.

Select all vertices (press A in editmode) then pres “Rem Doubles”

i feel ashamed so easy - and its working. Thank you.

Does anybody know how [a tutorial] how to fill bottle with water?