Changing Switches inside Scripts

[Zethzune]

I have walking sounds that are played from a parallel process common event, with four conditional branches (one for each directional key) these calls a second common event to play the footstep sound for the ground type of the area; however there is a problem with this method. Pressing directional on a choice message (dialog options) plays the footstep sounds. I don't want to put an event in every conversation to turn the footstep switches to 0, and then 1 when the message is gone.

So I want to toggle the switch in the window_message script.
I tried something like $game_switches.switch_id[0003] = 0

It would probably be better if somebody told me how moves were detected in scene_map so I can just put the sounds there (but I'd still have to check if switch 0003 (footsteps) was on or not)