What do you think about this? When you go to Dueling arena you click on Roster, then you click the persons name, then click Challenge. A new clipboard will appear and has a list of the amount of perk points to bet, type of plane, fields to take off from, fuel load, weapons load, etc. Then you click send and that person will get the list, he either clicks accept or decline. If he accepts both planes will launch at same time and no other planes will be able to take off from those fields until duel is over. Perks will automatically go to winner once they land. That way you can tell people to put their perks were their mouth is.