I was messing around with maplestory and i was pressing random buttons.. so this is an accidental discovery.
so here it is
1.Open up maplestory.
(for vista run in administrator.)
2.Go online.
3.Now your online press ALT+Enter.
As simple as that.
If you don't understand those 3 simple steps than you shouldn't be here.
I don't know if it works for other people but it works for me.