private void classYearError(String str) {
        //initialize variable
        String lead_in = "Format Error: Class Year: ";
        //return appropriate error message
        switch(str) {
            case "length":
                System.out.println(lead_in + "Incorrect Length");
                break;
            case "format":
                System.out.println(lead_in + "Incorrect Format");
                break;
            case "character":
                System.out.println(lead_in + "Incorrect Character(s)");
                break;
            case "year":
                System.out.println(lead_in + "Input Cannot Be Earlier Than " +
                        "Current Year");
                break;
            case "month":
                System.out.println(lead_in + "Input Cannot Be Earlier Than " +
                        "Current Month");
                break;
            default:
                System.out.println(lead_in + "Howdy, Saudis! Democracy has " +
                        "arrived.");
        }
        //exit program
        System.exit(4);
    }