The way you create a set of radio buttons is significantly different between Swing and the AWT. With Swing, you instantiate the buttons and add them to a group object rather than passing the group object as a parameter when you instantiate the buttons. To create radio buttons using the AWT, you instantiate a CheckboxGroup object and pass that object to the Checkbox constructor. Checkbox objects behave as mutually exclusive radio buttons and only one can be selected at a time. The following code was tested using JDK1.1.6 under Win95:

 import java.awt.*;import java.awt.event.*;import java.util.*;//=======================================================//public class RadioButton01 extends Frame{	public static void main(String[] args){		new RadioButton01();	}//end main	RadioButton01(){//constructor		//Create a CheckboxGroup object		CheckboxGroup myCheckboxGroup = new CheckboxGroup();		setLayout(new FlowLayout());    		add(new Checkbox("A",true, myCheckboxGroup));		add(new Checkbox("B",false,myCheckboxGroup));		add(new Checkbox("C",false,myCheckboxGroup));		setSize(250,100);		setTitle("Radio Buttons");		setVisible(true);    		// Inner class to terminate program.		addWindowListener(new WindowAdapter() {			public void windowClosing(WindowEvent e) {			System.exit(0);}});//end WindowListener	}//end constructor}//end class RadioButton01 definition