import java.applet.Applet;
import java.awt.*;
import java.util.*;
import java.io.*;

public class calc extends Applet {

	Button    continueButton;
	TextField textFieldAction, textFieldFirst, textFieldSecond, textFieldResult;
	int       ActionNumber, FirstNumber, SecondNumber, Result;
	String resString;
	
	public void init() {
	
		ActionNumber = 1;
		FirstNumber = 0;
		SecondNumber = 0;
		Result = 0;
		
		setLayout(new GridLayout(10,1));
			add(new Label ("Use these codes:",Label.CENTER));
			add(new Label ("1 = +  2 = -   3 = *  4 = /",Label.CENTER));
				textFieldAction = new TextField();
				add(textFieldAction);
			add(new Label ("Enter First Number:",Label.CENTER));
				textFieldFirst = new TextField();
				add(textFieldFirst);
			add(new Label ("Enter Second Number:",Label.CENTER));
				textFieldSecond = new TextField();
				add(textFieldSecond);
		continueButton = new Button ("CLICK to process");
			add(continueButton);
			add(new Label ("The result is:",Label.CENTER));
				textFieldResult = new TextField();
				add(textFieldResult);
			
	}
	
	public boolean action (Event HitReturnKey, Object arg) {
		
		if (HitReturnKey.target == continueButton) {
			ActionNumber = intFromTextField(textFieldAction);
			FirstNumber = intFromTextField(textFieldFirst);
			SecondNumber = intFromTextField(textFieldSecond);

				if (ActionNumber == 1) Result = FirstNumber + SecondNumber;
				if (ActionNumber == 2) Result = FirstNumber - SecondNumber;
				if (ActionNumber == 3) Result = FirstNumber * SecondNumber;
				if (ActionNumber == 4) Result = FirstNumber / SecondNumber;
				
			textFieldResult.setText(Integer.toString(Result));
		}
		return super.action(HitReturnKey, arg);
	}
	
	int intFromTextField(TextField tf) {
		String TextforConversion;
		int IntegerReturned;
			TextforConversion = tf.getText();
				try {
					IntegerReturned = Integer.parseInt(TextforConversion);
				}
				catch (Exception e) {
					IntegerReturned = 0;
				}
		return IntegerReturned;
	}
}