Millisecond Forums

We want to be able to test perseverance by giving participants an unsolvable calculation. They would get 5 minutes and can fill in several responses. After each response participants get the offer to choose whether they stop the task or whether they continue. If they continue they still have (5 minutes minus the time it took to response the first time). After the second response, they again get to choose whether they continue and if yes they should get (5min - (RT to response1+ RT to response 3)) and so on ...until a time out at 5 minutes.To be honest, I'm not sure how to start programming this. I will be one block, and I have one stimuli for the unsolvable exercise and one for the option to continue/stop. Can this all be done in one trial because I need two responses? Any help would be very welcome!! Thanks!!!