Come on guys, just coz hes new theres no reason to call him stupid
But yeah, u'll need to write a trigger which makes it so that when a unit enters x region the gate opens, and another that says if a unit leaves x region the gate closes.
NOTE: write a condition into the triggers that checks if the gate is alive: otherwise someone could destroy the gate, but then when someone leaves the region the gate will re-appear..
Bort