[help] Mouse game, how can this be done

I am making a mouse game were you have to click the right mc within a certain amount of time...

I have a MC with the varibale called box, a MC with the varible called tim, and a dyanmaic text box with the varible of scorer.

Every 5 seconds the will box will change colour and once tim reaches its 60th frame the box changes colour again ( i coppied the box MC and gave them the varibles of s1,s2,s3,s4) if you click the right one your score gose up 1 and if u click the wrong 1 your score goes down 1.

How could i make your score go down once tim reaches the 60th frame and you havnt clicked any of the boxes???

I have attached a .fla to show what i mean if u didnt understand

Just put in the "60th frame" a little code:

(if I remember right You used _root.score named variable as scores)
_root.score -=1;