Daft Question... about sound triggers...

[o'dium]

How do i add a trigger for a sound to be played, and then every time somebody passes through the trigger, the sound plays?

I know its stupid but after a hard day on portal particles ans scripting my minds just gone 100% blank. This is for Quake 4 BTW.

For some reason, I got it working but the sound cuts out after about a second... Its gonna be so fucking obvious i know it...