RPG MAKER 2003: INVOKE SKILL WHEN USED?

I was playing around rpg maker and I found this little option


Now, when I did insert a skill and checked the option I tried to test this mechanic out, however there didn't seem to be any change to the battle. Now am I doing something wrong? I assume that a skill should be launched as soon as you use the normal attack but there weren't any changes to the battle, seemingly.

EDIT: Nevermind, I have it figured out now :p