hightlight if/ifdef blocks

["Martin" <m.gercke@gmail.com>]

Hi,

after reading some rules about not nesting c comments and using #if 0
instead I tried it out in emacs.
But as it is at the moment, the blocks are not shown as if I would have
commented them out.
Is there an easy way of doing this?
The blocks should look  the same way as the comments usually look when
I add a //.
so

// not_used_at_the_moment();

should have the same color as
#if 0
not_used_at_the_moment();
#endif

I tried different things where people suggested that I make these
blocks invisible.
But since that's not what I want ...
Any suggestions?

Thanks in advance

Martin