Advance Gameboard, new blocks

First off Im new to the forums so hello everyone and bare with me on some of my questions(also new to mmf2) Ive managed to setup the advance game board in my game and have use the examples to get going(or at least start learning) I am trying to figure out how to make a new row of blocks fall after a certain amount of time has expired. I want the whole top row to appear randomly and then drop down to the bricks I have.

Any one get me started in the right direction. And I hope this is the right section for this post.