Good Afternoon All:

I am having some issues with exporting to PDF using the sketch below.  When I open the PDF, I should see 25 circles.  I am greeted with a blank PDF. I feel like I am missing something rather obvious but it isn't coming to me.

import processing.pdf.*;

int wDim = 9;    //dimension of width of printed paper
int hDim = 11;   //dimension of height of printed paper
int res = 72;    //Resolution of print in ppi
int cx = 0;      //Center of circle - x coordinate
int cy = 0;      //Center of circle - y coordinate
int sw = 0;      //Strokeweight
int rd = 0;      //Radius of circles
int h = 0;       //Hue value
int s = 0;       //Saturation value
int co = 0;      //Counter

void setup() {
  wDim = wDim * res;    //Reset width of paper for ppi
  hDim = hDim * res;    //Reset height of paper for ppi
  size(wDim, hDim, PDF, "c:/balloons.pdf");     //Set size of window
  background(255);      //Set background to white
  stroke(0);            //Set stroke to black
  smooth();             //Turn on anti-aliasing
  colorMode(HSB, 100);  //Switch to HSB color mode
}

void draw() {
  co = co + 1;
  cx = int(random(wDim));                //Pick a random x for the circle center
  cy = int(random(hDim));                //Pick a random y for the circle center
  rd = int(random(10, 100));             //Select a random radius between 10 and 100
  sw = int(random(1, rd/20));            //Select a random strokeweight between 1 and 5
  strokeWeight(sw);                      //Set strokeweight
  h = int(map(cx, 0, wDim, 0, 100));     //Convert cx into a hue value
  s = int(map(cy, 0, hDim, 100, 0));     //Convert cy into a saturation value
  fill(h, s, 100);                      //Set new fill value
  stroke(h, 100-s, 100);
  ellipse(cx, cy, rd, rd);               //Construct circle
  println(co);
  if (co == 25){
    println("finished");
    exit();
  }
}