Making multiple blocks rise and fall with a sensor.

[durf]

Hello,

Im trying to make a program that interacts with a sensor(ppt). Ill describe what I am trying to do:

Imagine a checkerboard.... each checker represents a block. The checkerboard is located horizontally on the x axis with a position starting position at lets say -10 on the y- axis.

The object of this program is when the ppt crosses over one of these blocks the block rises to y = 0. As the ppt moves off of the block the block falls back to y = -10.

My questions:

What is the best way to arrange all of these blocks at -10? position each image myself? a loop?(its the same image by the way just multiples of it)

How do I tell the block to rise when the sensor crosses over it?

What is the best way to make the block fall back to -10? gravity?

If I could just get some answers to get me going on this it would be much appreciated.

Thanks

Barry