How do I verify that TRIM is activated? (Linux)

I have kernel*.32 and I use ext4 on my drive. Now I just don't know how to check if trim support is enabled?

Found this: http://blog.patshead.com/blog/2009/12/a-quick-and-dirty-wipersh-fix-for-intel-x25-m.html

The TRIM command has only been supported on Ext4 since kernel version 2.6.33. It is disabled by default (as it is slightly experimental), but can be enabled with the mount option "discard".

When calling 'mount' on the CLI you should get a response that looks similar to:

/dev/sdx on / type ext4 (rw,noatime,discard,errors=remount-ro,commit=0)

Note the discard option is present, which signifies the volume is mounted with the TRIM option.