import java.util.Scanner;

public class InvoiceApp
{
   public static voice main(String[] args)
   {
     //welcome the user to the program
     System.out.println("Welcome to the Invoice Total Calculator");
     System.out.println();    // print a blank line
    
     // create a Scanner object named sc
     Scanner sc = new Scanner(System.in);
     
     // perform invoice calculations until choice isn't equal to "y" or "Y" 
     String choice = "y";
     while (choice.equalsIgnoreCase("y"))
     {
       // get the invoice subtotal from the user
       System.out.print("Enter subtotal: ");
       double subtotal = sc.nextDouble();

       // calculator the discount amount and total
       double discountPercent = 0.0;
       if (subtotal >= 200)
           discountPercent = .2;
       else if (subtotal >= 100)
           discountPercent = .1;
       else
           discountPercent = 0.0;
       double discountAmount = subtotal * discountPercent;
       double total = subtotal - discountAmount;

       // display the discount amount and total
       String message = "Discount percent: " + discountPercent + "\n" 
                      + "Discount amount: " + discountAmount + "\n" 
                      + "Invoice total: " + total + "
\n";
       System.out.println(message);
       
       // see if the user wants to continue
       System.out.print("Continue? (y/n): ");
       choice = sc.next();
       System.out.print();


     }
     

   }



}

*******************************************************

output:

Welcome to the Invoice Total Calculator

Enter subtotal: 150
Discount percent: 0.1
Discount amount: 15.0
Invoice total: 135.0

Continue? (y/n): _