Help with serials and strings

Hi Processing Forum,

I am in the process of hacking a rotary phone, using Arduino and Processing to convert the phone into a recording and playback device. It is a really interesting project and I have made some progress, but I got stuck on a string from the serial port. My code is long, so I will share my public gist here: https://gist.github.com/lizzybrooks/b88531b906860d4fc4af.

Here is the function that seems to be giving me trouble:

void readNumbers(){
if ( myPort.available() > 0) 
  {  
    // get the value from the serial port
    do{
    val = myPort.readStringUntil('\n');         // read it and store it in val 
    } while (val == null);

    // print every value received to the console so we know what we got
   // println(val);
   // println(val.length()); 

if (val.equals("6\r\n")){
      println("hooray. you work. let's play a different audio file");

      // anything else and its input from the phone
      // so do whatever you want if you receive input from the phone here...
    }

  }

If you have any ideas or can help me with syntax, I would so much appreciate it. I am a beginner coder working on a complicated project, but I am eager to learn.

Thanks so much!

Lizzy