How to declare a new variable

Greetings.
I'm using a j3iB with a R-2000iA 165F i have been programming with the teach pendant, but now i need to declare a new variable to use as a counter, does anyone know if there is a way to do this?

Quote from Nation

You don't really declare variables in Fanucs. You just use a register that isn't used anywhere else in your program.

That help me a lot, thanks