// This program creates a screen with two textboxes and a button. // When the user clicks the button, a label displays the result // which is the sum of the numbers in the two textboxes. // Modify the program to allow the user to click any // of three buttons. On displays the sum of the two numbers. // The others display the difference and product respectively. start Declarations Screen screen1 Button calcButton Textbox usersEntry1 Textbox usersEntry2 Label result screen1.setSize(200, 200) calcButton. setText("Click to sum the numbers you have entered") calcButton. registerListener(sumNumbers()) screen1.add(usersEntry1) screen1.add(usersEntry2) screen1.add(calcButton) stop sumNumbers() Declarations Label result num sum string answer sum = usersEntry1.getText() + usersEntry2.getText() answer = "The sum of the numbers is ", sum result. setText(answer) screen1.add(result) return