Fun with Rotary Encoders

Hey, quick update. My processing code right now:

// Example by Tom Igoe

import processing.serial.*;

Serial myPort;  // The serial port
PImage img;
String val;
int lf = 10;
int cr = 13;

void setup() {
  size(1280, 1280);
  img = loadImage("FriendlyFire_0.png");
  // List all the available serial ports
  // Open the port you are using at the rate you want:
  myPort = new Serial(this, Serial.list()[0], 9600);
  myPort.bufferUntil(lf);
}

void draw() {
  image(img, 0, 0);
  //loadImage("FriendlyFire_" + val + ".png");  
}

void serialEvent(Serial p) { 
    // Expand array size to the number of bytes you expect
  byte[] inBuffer = new byte[7];
  while (myPort.available() > 0) {
    myPort.readBytes(inBuffer);
    if (inBuffer != null) {
      String myString = new String(inBuffer);
      println(myString);
      val = myString;
    }
  }
}

My input in the serial monitor:

47

1

2

3

What it looks like when I try to load images:
The file "FriendlyFire_null.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.
The file "FriendlyFire_null.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.
22
The file "FriendlyFire_22
** .png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.**

Etc.

I apologize for my over newness. How do I assign the output of myString to val?