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

public class interest extends Applet implements implements ActionListener
{    

    simple sim;                           //simple is the simple interest class
    compound com;                    //compound is the compound interest class.

   TextField price, roi, years, down_payment;  //use four textfields for input
   Checkbox simp,comp;                                      //one check box for simple or compound
   Button  submit, reset;                           //two buttons  
Label y,r,p,d;                                         //display labels for information

    public void init()
    {

//create instances of labels here

    price = new TextField("0",10);
    roi = new TextField("0",10);
    years = new TextField("0",10);
    down_payment = new TextField("0",10);
    submit=new Button("Submit");
    cancel=new Button("reset");
    simp=new CheckBox("Simple Interest",true);
    comp=new CheckBox("Compound Interest");
     
    submit.setActionCommand("submit");
    submit.addActionListener(this);

    reset.setActionCommand("reset");
    reset.addActionListener(this);


        //Use a GridLayout with 2 columns and any number of rows
        //and 5 pixels of padding around all edges of each cell.
        setLayout(new GridLayout(0,2,5,5));    

        //add all the components to the applet in order

       validate();
}


    public void start()
    {

    }

    public void stop() 
    {

    }
    

    public void destroy() 
    {

    }

public void actionPerformed(ActionEvent e) 
{
if ("submit".equals(e.getActionCommand())) 
{
//add code here to display the interest
}

if ("reset".equals(e.getActionCommand())) 
{
//add code here to reset the fields
}   
}

}

JRadioButton simp,comp;

            private ButtonGroup radioGroup;

       simp=new JRadioButton("Simple Interest",true);  //create two radio buttons
       comp=new JRadioButton("Compound Interest");
       
       radioGroup = new ButtonGroup(); //new group. add simp and comp to the group
       radioGroup.add( simp );
       radioGroup.add( comp ); 

   simp.setBounds(220,50,150,20);    //set bounds
   comp.setBounds(220,70,150,20);

   RadioButtonHandler handler = new RadioButtonHandler();

   simp.addItemListener( handler );   //add item listener
   comp.addItemListener( handler );

   contentPane.add(simp);             //add to the pane
   contentPane.add(comp);

   // private inner class for ItemListener event handling
   private class RadioButtonHandler implements ItemListener 
   {

        public void itemStateChanged( ItemEvent event )
        {
           if ( event.getSource() == simp )  //check whether simp is the source
           {
              if ( event.getStateChange() == ItemEvent.SELECTED )
              {
                   //add code here
              }
           }

           if ( event.getSource() == comp )  //check whether comp is the source
           {
              if ( event.getStateChange() == ItemEvent.SELECTED )
              {
                  //add code here
              }
           }
       }
   }

class simpleInterest
{
      public int price, roi, downpayment, years;

      public float interest;

      public calculate( int fprice, int froi, int fdownpayment, int fyears)
      {
            //add code to calculate the simple interest here
      }
}

simpleInterest sim;
compoundInterest com;