How to make "borderlines" ?

[Echo-Zero]

Hi,

Any1 here know how to make a borderline..like a no-fly zone?

Ive seen in it other maps..

the reason i need it cuz you keep dying and dying within a couple of seconds. lol

Thanks,

[Echo-Zero]

Nevermind, finally found it, called combat area.
know how it works now. :)