import?java.awt.BorderLayout;
import?java.awt.Color;
import?java.awt.Dimension;
import?java.awt.Font;
import?java.awt.GridLayout;
import?java.awt.event.ActionEvent;
import?java.awt.event.ActionListener;
import?java.text.DecimalFormat;

import?javax.swing.BorderFactory;
import?javax.swing.ButtonGroup;
import?javax.swing.JButton;
import?javax.swing.JCheckBoxMenuItem;
import?javax.swing.Jframe;
import?javax.swing.JMenu;
import?javax.swing.JMenuBar;
import?javax.swing.JMenuItem;
import?javax.swing.JPanel;
import?javax.swing.JRadioButtonMenuItem;
import?javax.swing.JTextField;

public?class?Calucator?extends?Jframe?{
????private?JTextField?tf;
????private?JPanel?panel1?panel2?panel3?panel4;
????private?JMenuBar?myBar;
????private?JMenu?menu1?menu2?menu3;
????priva