[Mark McLeod]

Here are two answers.

The first picture goes to the root of what you need to do to set a solenoid. It doesn't bother to remember the last value sent to the solenoid, because the solenoid will remember whatever it was last set to. It doesn't need to be set to the same value over and over.

The second picture remembers the value from the last button pushed and keeps setting the solenoid to it over and over again even though it's an unnecessary action.

There are still more ways to accomplish this kind of action. These are only examples.
Variables are not used in LabVIEW, a data flow language, the way you'd use them in a procedural language.