Hard Array Problem I need to overcome.

Basically I need to randomly generate bricks on the screen and when you click them they explode. This is just a hobby atm.

Heres what I need to do:

I need to create in some ways a 2d array that produces a table with 20 different slots.

I then need to be able to use a for next loop to randomly assign a brick in that table until you click it and it explodes.

How would I create the table so that I can only ever randomly display a brick in 1 of the empty slots?

Many Thanks for all the help,

JamesĀ