GUI Quiz Points System Help!

[Newspaper]

Hi guys.

I am making a quiz for my final project which has 3 difficulties. I am using GUI. Each time a response is selected (A,B,C or D) it displays a message saying weather it was right or wrong. What I am having trouble with is getting the points tallied up because each time you get it wrong you lose a point from your total available points of 3 per question. There are 10 questions per difficulty. The wrong or right is in an if statement

E.g

if blah blah then
wrong
avPoints := avPoints - 1
elsif
correct
totalpoints := avPoints + totalPoints
etc.

I was wondering how I would get that to add up once it is correct and then add that to each question untill a grand total out of 30 is accumulated.

Thanks