Can anyone tell me what's wrong with this code?

use double = IF B==8 THEN...

Another way to use buttons B=BUTTON() IF B AND #UP THEN IF B AND #A THEN IF B AND #Y THEN a lot easier.

You are placing and removing the ASCII dude before the VSYNC happens. I recommend clearing the spot using LOCATE X,Y:? " " or CLS, moving the XY coordinate, and placing the dude im that order before the VSYNC. It's simpler that way.