How can this be done?

Hi all, using a trigger that lays card 11 in hilo for £4 and backs the favourite each round for £4, the trigger starts backing no later than round 12 but backs card 1 or further twice which sometimes results in a £4 loss if it loses in round two so i want to know how i can set it to only back a selection once i.e in this case card 1 or futher once only?


Any ideas on this would be appreciated


Thanks in Advance - Paul

Add this to the trigger:
Selection's Lay Matched is equal to 0