I see you've posted this question in another thread as well, and I answered there.

>>Now, one caveat. There are some key combinations that don't work on all machines, but it seems to be more a function of the BIOS intercepting them then anythings else. What those keys are differs from BIOS to BIOS, so you can't be sure.
>
>Barbara,
>
>And how can I catch these keys:
>
>CTRL+HOME
>CTRL+END
>PAGEUP
>PAGEDOWN
>F12
>
>Thanks in advance.