combat styles change using PS3

Hi
I've just bought Virtua Fighter 5 and I've seen that many characters have different movements based on different combat style.
The question is : how do I switch from one combat style to another ? for example using Vanessa from offensive to defensive mode ?.

Thanx in advance

 

Thanks a lot.
It is strange that such an important feature it is not mentioned on the instructions with the game.
I've noticed that many charatcer use the same button combination to do the combat style switch.

 

if you gothrough thecommand list it'll teach you all the moves, incuding how to witch stance (it's usually called stannce)