Where is the "SubSurf" button?

Hello.

I’m a newbie.

I’m now reading the “User Guide”, and it’s written, here:

http://download.blender.org/documentation/htmlI/ch04s02.html

That there’s a “SubSurf” button. But I can’t find it!

I’m attaching a screenshot of my system (click to enlarge):

http://img58.imageshack.us/img58/9756/screenshot0zk.th.png

I’ve encircled, in red, the place where, according to “Figure 4.16” in the User Guide, this “SubSurf” button is supposed to be. As you can see, it’s empty.

Where can I find it? %|

In F9 buttons window under Modifiers.

%<

I think this must qualify as the most asked question on elysiun in the last month.

For the record, you may want to take a look here:
http://mediawiki.blender.org/index.php/Manual/PartI/Your_First_Animation_in_30_plus_30_Minutes_Part_I#Temporary_link_to_the_update_to_2.40_I_am_working_on

This is the updated version of the Gus tutorial (work in progress though) and will save you a lot of headaches since some things are easier now than they were before.