How to make code count boxes?

I am trying to recreate Deal or No Deal on Matlab. I have scrambled the cases so the values of the boxes will be different, however I am trying to make it so at the start of the game when you click a box this becomes 'your box'. Then the rest of the game plays out as normal.

I am struggling to make the code realize that once 'your box' has been picked, it should play the game out as normal. Can anyone help with this?

I have attatched relevant bits of code.

Thanks for your help