COM Port Error: Port Not Found

Processing Electronics (Arduino, etc.)
18 
/*--------------------------------------------------------------
  Program:      port_find

  Description:   
                
  Date:         1 November 2012
 
  Author:       W.A. Smith, http://startingelectronics.org
--------------------------------------------------------------*/
import processing.serial.*;

Serial ser_port;                // for serial port
PFont fnt;                      // for font
int num_ports;
boolean device_detected = false;
String[] port_list;
String detected_port = "";

void setup() {
    size(400, 200);                         // size of application window
    background(0);                          // black background
    fnt = createFont("Arial", 16, true);    // font displayed in window
    
    println(Serial.list());
    
    // get the number of detected serial ports
    num_ports = Serial.list().length;
    // save the current list of serial ports
    port_list = new String[num_ports];
    for (int i = 0; i < num_ports; i++) {
        port_list[i] = Serial.list()[i];
    }
}

void draw()
{
    background(0);
    // display instructions to user
    textFont(fnt, 14);
    text("1. Arduino or serial device must be unplugged.", 20, 30);
    text("   (unplug device and restart this application if not)", 20, 50);
    text("2. Plug the Arduino or serial device into a USB port.", 20, 80);
    
    // see if Arduino or serial device was plugged in
    if ((Serial.list().length > num_ports) && !device_detected) {
        device_detected = true;
        // determine which port the device was plugge into
        boolean str_match = false;
        if (num_ports == 0) {
            detected_port = Serial.list()[0];
        }
        else {
            // go through the current port list
            for (int i = 0; i < Serial.list().length; i++) {
                // go through the saved port list
                for (int j = 0; j < num_ports; j++) {
                    if (Serial.list()[i].equals(port_list[j])) {
                        break;
                    }
                    if (j == (num_ports - 1)) {
                        str_match = true;
                        detected_port = Serial.list()[i];
                    }
                }
            }
        }
        ser_port = new Serial(this, detected_port, 9600);
    }
    // calculate and display serial port name
    if (device_detected && ser_port == null) {
        text("Device detected:", 20, 110);
        textFont(fnt, 18);
        text(detected_port, 20, 150);
        ser_port = new Serial(this, detected_port, 9600);
    }
}