I'm new in processing and for my code I wanna display a picture after the mouse released and the picture can't be same for each time .can anyone help me to change the code.also there is a outofmemory error.
Need help!!!


import ddf.minim.*;
Minim minim;
//AudioPlayer player;
ParticleSystem ps;
PImage[] story = new PImage [23];
PImage a;





void setup() {
  size(800 , 600) ;
    minim = new Minim (this);
    player = minim.loadFile ("music1.mp3");
    player.loop();
  ps = new ParticleSystem(1, new PVector(width/2,height/2,0));

}


void draw(){
 // a=loadImage("a1.jpg");
  //  background(a);
  int randomNum = (int) random(23);
    story[randomNum]=loadImage(randomNum+".jpg");
    if
    if(mousePressed){
  image(story[randomNum],0,0);
    }
   

  ps.run();
  ps.addParticle(mouseX,mouseY);
 
  
 
}

class ParticleSystem {

  ArrayList particles;  
  PVector origin;      

  ParticleSystem(int num, PVector v) {
    particles = new ArrayList();            
    origin = v.get();                      
    for (int i = 0; i < num; i++) {
      particles.add(new Particle(origin));   
    }
  }
 




  void run() {
    for (int i = particles.size()-1; i >= 0; i--) {
      Particle p = (Particle) particles.get(i);
      p.run();
      if (p.dead()) {
        particles.remove(i);
      }
    }
  }

  void addParticle() {
    particles.add(new Particle(origin));
  }
 
    void addParticle(float x, float y) {
    particles.add(new Particle(new PVector(x,y)));
  }

  void addParticle(Particle p) {
    particles.add(p);
  }

  boolean dead() {
    if (particles.isEmpty()) {
      return true;
    } else {
      return false;
    }
  }

}


class Particle {
  PVector loc;
  PVector vel;
  PVector acc;
  float r;
  float timer;
 
  Particle(PVector l) {
    acc = new PVector(0,0.05,0);
    vel = new PVector(random(-1,1),random(-2,0),0);
    loc = l.get();
    r=15;
    timer = 100.0;
  }

  void run() {
    update();
    render();
  }

  void update() {
    vel.add(acc);
    loc.add(vel);
    timer -= 1.0;
  }

  void render() {
    ellipseMode(CENTER);
    stroke(255,timer);
    fill(100,timer);
    ellipse(loc.x,loc.y,r,r);
  }
 
  boolean dead() {
    if (timer <= 0.0) {
      return true;
    } else {
      return false;
    }
  }

}