int i = 0;
    do {
      System.out.print("Please enter the product ID to purchase.");
      String orderItem = input.nextLine();
      if (orderItem.toUpperCase() == "13WB") {
        orderNum[i] = productIDs[0];
      }
      else if (orderItem.toUpperCase() == "18WB") {
        orderNum[i] = productIDs[1];
      }
      else if (orderItem.toUpperCase() == "23WB") {
        orderNum[i] = productIDs[2];
      }
      else {
        System.out.print ("Error. Please enter a product ID.");
      orderItem = input.nextLine();
      }
      System.out.println(orderNum[i]);
      System.out.println("You entered product ID: " + orderItem);
      i ++;
      System.out.print("Would you like to order another item? \n"
                         + "Enter 'y' for yes, 'n' for no.");
      doAnother = input.nextLine();
    }

    while (i < SIZE && doAnother.toLowerCase() == "y");