Implementing code to scroll left and right on top subplot

Below I have linked my files, cell plot creates plots and from alpha_test data. test1 contains code that should allow for me to use both left and right arrow keys to view certain sections of the top subplot but for whatever reason it does not allow for this to occur. Would anyone be willing to try to debug this issue? Thanks

[Robert Guzek]

Also, is there a way to select the first and last data points from the second subplot and put them into an equation?