Building a basic Currency Converter

Question

Hi, I am trying to build a pounds to euro, euro to pounds currency converter. The user enters the current exchange rate, what they want to convert and how much. I am trying to use a main class as a command line interface and a class to do the maths. My problem is trying to get them working together as I'm not great with classes. This is what I have so far... the problem is with the Converter converter = new Converter(); line. If I hover over the error symbol in Netbeans it says 'Cannot find symbol'.
package Assignment1;
import java.util.Scanner;
* @author Aaron
public class Interface {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        Converter converter = new Converter();
        double exchangeRate;
        int convertOption;
        double amount = 0;
        System.out.println("Welcome to the Currency Converter!");
        System.out.println("Please enter the current exchange rate for " +
                "Pounds to Euros");
        exchangeRate = scan.nextDouble();
        System.out.println("Convert Pounds to Euros (1) or Euros to Pounds" +
                "(2)");
        convertOption = scan.nextInt();
        while (convertOption == 1 || convertOption == 2) {
            System.out.println("How much would you like to convert?");
            amount = scan.nextDouble();
        if (convertOption == 1) {
            amount = converter.poundToEuro(exchangeRate, amount);
            System.out.println("" + amount);
        if (convertOption == 2) {
            amount = converter.euroToPound(exchangeRate, amount);
            System.out.println("" + amount);
        if (convertOption != 1 || convertOption != 2) {
            System.out.println("Not a valid option. Please re-run the " +
                    "program.");
package Assignment1;
* @author Aaron
public class Converter {
    private double exchangeRate;
    private double amount;
    private double result;
    public Converter(double exchangeRate, double amount, double result) {
        this.exchangeRate = exchangeRate;
        this.amount = amount;
        this.result = result;
    public double poundToEuro(double exchangeRate, double amount) {
        result = amount * exchangeRate;
        return result;
    public double euroToPound(double exchangeRate, double amount) {
        result = amount / exchangeRate;
        return result;
}

Answer 1

By the way:
There's absolutely no need to do the string appending here:
            System.out.println("" + amount);Creating a field to hold values to return from methods is unnecessary and poor form; just make them local variables:
public class Converter {
    private double result;
    public double poundToEuro(double exchangeRate, double amount) {
        result = amount * exchangeRate;
        return result;
    }I second the suggestion not to name your class "Interface". It's syntactically OK (because the keyword is lower-case) but it's still confusing.