I need help, with a shooting gallery type game. Targets are going to pop up at random at a random location and you have to click them to score. What i currently need help with is the Random locations and the Hit detection. So far the enemy (smiley) just sits in the left corner of the program, and does nothing. I haven't got any hit detection at all, simply because i'm not to sure how to do it.
Here's my code so far:

float r;
float rx;
float ry;
float x;
float y;
float px;
float py;
PImage Ch;
PImage Bh;
float Bx;
float By;
float distance;
PImage Enemy;
int Score;
boolean bDisplay;
boolean bDisplay2;
boolean bDisplay3;
boolean bDisplay4;
boolean bDisplay5;
boolean bDisplay6;
boolean bDisplay7;
boolean bDisplay8;
boolean bDisplay9;
boolean bDisplay10;
color c =(255);
color col;
int enemyRadie = 50;
int i;
Smiley[] smiler = new Smiley[10];
PFont f;
float m;
class Smiley {
  int x;
  int y;
  boolean visible;
  PImage picture;

  Smiley(PImage enemy, int px, int py) {
    picture = enemy;
    px = x;
    py = y;
    visible = true;
  }
}


void setup()
{
  size (800,600);
 Ch = loadImage ("crosshairs.png");
 Bh = loadImage ("BulletHole.png");
 Enemy = loadImage ("Awesome Smiley.png");
 Score = 0;
   for(int i = 0; i < smiler.length; i++) {
    smiler[i] = new Smiley(Enemy, (int)random(width-100), (int)random(height-100));
  }
 f = loadFont("Text.vlw");


 }


void draw()
{
  background(0,200,0);
  textFont(f,25);
  float r = random(0, 600);
  float rx = random (0, 800);
  float ry = random (0, 600);
  float m = millis();
  noCursor();
  image (Ch, mouseX,mouseY);
  for(int i = 0; i < smiler.length; i++) {
    if(smiler[i].visible == true) {
      image(smiler[i].picture, smiler[i].x, smiler[i].y);
    }
  }
  text (Score, 25,25);
  text (m, 700,25);
  {

   

  }
}
{
if (m >= 60000){
noLoop();
text ("Time's up. Your score is" +Score,200,200);
}
}
void mousePressed()
{ 
  for (int i = 0; i <10; i++){
   float distance = sqrt( px*px + py*py );}
    if(distance <50){
          bDisplay = false;
    bDisplay2 = false;
    bDisplay3 = false;
    bDisplay4 = false;
    bDisplay5 = false;
    bDisplay6 = false;
    bDisplay7 = false;
    bDisplay8 = false;
    bDisplay9 = false;
    bDisplay10 = false;
    println("Check");

    Score = Score + 50;}
}