function FirethrowProjectile::onCollision(%this,%obj,%col,%fade,%pos,%normal)
{
%col.schedule(1000, "damage",0, "0 0 0", 5, "Fire");
%col.schedule(2000, "damage",0, "0 0 0", 5, "Fire");
%col.schedule(3000, "damage",0, "0 0 0", 5, "Fire");
%col.schedule(4000, "damage",0, "0 0 0", 5, "Fire");
}
this is the code you are looking for.