What screws do I use to attach my mobo to case?

[gingo]

my case came with a bunch of screws, so are longer than others, some have round heads, some dont, which ones do I use for attaching the mobo to the brass standoffs?

does it matter?

 

[elBogg]

as long as they screw into the mobo standoffs okay they should be fine. shouldn't be the long ones, though.