Very Easy Question - It must be late....

How do you make it so that a trigger does an action, after a unit has entered a region, and stayed there for 5 seconds? It must be late....Im feeling sleepish and outta it... :////

Try this:

Event:
Unit x enters region y

Action:
Turn off this trigger
Wait 5 seconds
If region y contains unit x then do .... else do nothing

Thanks...I knew it was something stupid :D