How do I do this..?

[Ecnarf]

Ok so what I am trying to do is basically if a picturebox = a certain image then it will or wont do certain things depending on its image. I am making a custom UI for my program as I usually do but, I have never done what I am trying now. I am making some nice custom tabs but, would like it so they can tell which one is selected if they are over the one that isn't selected and are about to select it or if its just plain and not selected at all.