Button properties

Well, thank you for telling me what a bad idea is. You gave me enough information to correct my mistakes.Rather than confusing you further, I'll try to describe the scenario. There are 3 units, so there are three buttons (U1, U2, U3). The user starts from U1 and the button U1 will be navy while the other two buttons will be grey. When the user starts U2, both U1 and U2 buttons will be navy with just one that remains grey.The reason is that I want to tell the user where he is, where he has been and what is coming next. Navy buttons are active - the user can jump among units - grey buttons are not.