Here is a case structure inside of an event structure that will do exactly what you want.
Not to sound preachy or anything, but the questions you asked showed a pretty significant lack of understanding on how case structures work. Since they are one of the most fundamental parts of LabVIEW programming, I suggest you spend awhile familiarizing yourself with them before moving on. The help files are useful, but just playing around for awhile is also useful. Good luck!
Edit: I forgot to add this to the VI, but you should also look in to local variables. You just right click on the terminal in the back panel, -> Create -> Local Variable
