Changing a script variable ingame

[Skyline]

I've returned to scripting after a very long absence from RMXP, and now i'm trying to script again.

I've started off by making a Currency script, but I can't remember how the hell you change a variable from "True" to "False" ingame.

I was thinking something along the lines of(In the "Script..." function in the event commands):

Scene_Currency.currency = true

But i'm not 100% on that.

Any help?