import java.util.Scanner;
import javax.swing.JOptionPane;


public class StartClass {

	public static void main(String[] args) {

		Scanner input = new Scanner(System.in);
		String value;
		double width, length, area;
		boolean repeat = false;
		do {
			try {
				value = JOptionPane.showInputDialog("Enter length rate: ");
				length = Double.parseDouble(value);

				value = JOptionPane.showInputDialog("Enter width: ");
				width = Double.parseDouble(value);

				area = length * width;
				JOptionPane.showMessageDialog(null, "Area is : " + area);

				repeat = false;
			} catch (NumberFormatException e) {
				JOptionPane.showMessageDialog(null, "Error! Enter numeric value only!", "Data input Error", JOptionPane.ERROR_MESSAGE);
				repeat = true;
			}
		} while (repeat);
		input.close();
	}
}