Definitions

So DrRackert let's me make definitions in the top window, but then it calls these constants, like if I do a simple

(define a 10)

If I try to re-define or set! a 15 then the interpret gets angry and says that a is a constant

How do I define something that can change values?

>>13
Great! It no longer gives me an error.

Unfortunately, it doesn't change the screen width/height BUT it does change that value, and that is absolutely useful. Probably something to do with the screen-size maker thing running only once, then it continuously draws the stuff inside it, or even a single frame, I can't decipher this code.

The code was copypasta from a google groups on OpenGL, I did not do indenting or anything