  angular.module('invoice1', [])
    .controller('InvoiceController', function() {
      this.qty = 1;
      this.cost = 2;
      this.inCurr = 'EUR';
      this.currencies = ['USD', 'EUR', 'CNY'];
      this.usdToForeignRates = {
        USD: 1,
        EUR: 0.74,
        CNY: 6.09
      };

      this.total = function total(outCurr) {
        return this.convertCurrency(this.qty * this.cost, this.inCurr, outCurr);
      };
      this.convertCurrency = function convertCurrency(amount, inCurr, outCurr) {
        return amount * this.usdToForeignRates[outCurr] / this.usdToForeignRates[inCurr];
      };
      this.pay = function pay() {
        window.alert("Thanks!");
      };
    });