OFF-Ball Button in NBA 2k9 PC Version? and more.

[Jerson]

Hello, I'm just new in NBA 2K9 and I'm still confuse about its controls.
My question is how can I use the OFF-Ball button feature?
What should I click in order to be in OFF-Ball Mode?

and

How can I call for alley-oops? again
What should I click?

&

How can I call for plays? and what are B1, B2, B3, B4, up to B12?

Thanks for your help...

[SkyLine03LT]

to throw an alley-oop pass hold the "post up" button and press "pass"