Slice replace/select

Hello all,
I am making a game of sorts and I am having difficulties with the logic in Gamma as i am pretty new with it.
the basic idea is simple: one side of the screen there is a grid of 36 rectangles that by default display the first image from a folder, on the left is a grid of 12 different images.

the idea is as follows:
You select one of the 36 rectangles, then you select what image should be on it form the 12 image grid.
It almost works but not quite. I am way too new with gamma and some things are different from the way i got used to in Beta.
For now it works but it always swithches the last slice as the mouse leaves the selected area.

Anyone willing to point me in the right direction? Thanks! (63.2 KB) (66.1 KB)

Something like this? Used a pad to save your paths on create. if the condition apply in the if region, the values in the pad are changed. And some more logic and another s+h node.

Exactly what I needed! Thank you!

The idea of the game is for 2 kids to play, they trow a pair of dice/pull a note with math equation and then mark their mathematical result on the big grid.
Need to split the big grid in two groups so it is more separated and be easier to track and click individual results.