#final processing code

int val = 0;

PImage img1; PImage img2; PImage img3; PImage img4;

void setup() {  size(displayWidth,displayHeight);  background(241,238,251);  noStroke();  img1 = loadImage("3-01.png");  img2 = loadImage("11-01.png");  img3 = loadImage("11-01-01.png");  img4 = loadImage("11-01-01-01.png"); }

void draw(){ switch(val){

 case 0: background(0);  break;

 case 1:   image(img1,0,0,width,height);  break;

 case 2:   image(img2,0,0,width,height);  break;

 case 3:   image(img3,0,0,width,height);  break;

 case 4:   image(img4,0,0,width,height);  break; } }

 void keyPressed(){    if (key == 'D'){    val = val + 1;    if(val > 4){      val = 0;

     println(val);