How do I incorporate a selective statement in the code below?

How do I incorporate a selective statement in the code below?

Clarification

1. Demonstrate your understanding of GUI.
2. Use selection and repetition statements in this program.

import java.text.DecimalFormat;

import javax.swing.JOptionPane;

public class module3case {

   public static void main(String[] args) {

      String choice = null;

      do {

         DecimalFormat formatter = new DecimalFormat("#,##0.00");

         double propertyTaxRate;

         double actualValue;

         double assessmentValue;

         double tax;

         actualValue = Double.valueOf(JOptionPane.showInputDialog("What is the value of your property?"));

         propertyTaxRate = Double.valueOf(JOptionPane.showInputDialog("What is the property tax of the locality?"));

         tax = actualValue * propertyTaxRate/100;

         assessmentValue = actualValue +tax;

         JOptionPane.showMessageDialog(null, "Your assessment value is $"

                + formatter.format(assessmentValue)+"n"

                +"The local real estate property tax rate: "+propertyTaxRate+"n"

                + "Property tax based on the assessment is $"

                + formatter.format(tax) + ".");

         choice =JOptionPane.showInputDialog("Press E to terminate the program ");

         }while(!"E".equalsIgnoreCase(choice));

   }

}