How to update GUI in real time?

It may seem simple, but here goes:
I have a GUI Label next to a GUI button. I want clicking the button to change what the label says. I’ve been able to do this but only if the scene is reloaded. How do I change the button in real-time?
JavaScript is all I know!

I’m not sure where the problem is. It would sure help if you could provide the code you wrote.

Nevertheless, if a GUI.Label displays a string and the GUI.Button changes this string, naturally the Label would show the change, why wouldn’t it?