Wireless Nerf Gun Processing

import processing.serial.*;

PImage img;

Serial port;

void setup() {
  size(960,540);
  //img = loadImage("GUI.JPG");
  port = new Serial(this, "COM12", 9600);
}

void draw() {
   //image(img, 0, 0);

}
//function to check for a keyboard key press during the draw loop
void keyPressed(){
  switch(key) {
  case 'w':
   port.write(0);
   break;
  case 's':
   port.write(1);
   break;

  case 'a':
   port.write(2);
   break;
  case 'd':
   port.write(3);
   break;
  case 'x':
   port.write(4);
   break;
  }
}