This just an example, with item trade, (this will trade a breadcake for a skin of milk.) I use this simple one for various npc's I have. (with different items)
	Code:
	sub EVENT_ITEM {
	if(plugin::check_handin(\%itemcount, 13005 => 1)) {
		quest::say("Thank you $name, here is the item you traded for.");
		quest::summonitem(13006);
	}
	else {
         #quest::say("I have no use for this, $name. You can have it back");
         plugin::return_items(\%itemcount);
    }
}