Program works but..........

Question

My program works. It is a program to track rainfall during a week. You enter in a number, hit enter, then click the box and the number will appear in the box. The problem is you can click outside of the box and get the same results. How can I get it to when you click outside the box, nothing will happen, only when you click inside the box something will happen. I hope this makes sense.
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class Rainfall extends Applet implements ActionListener,
                                                                      MouseListener
{//begin class
protected Table rainData;
protected TextField value;
protected int newValue;
protected int yCoord;
protected int index;
protected int sum = 0;
     public void init()
     {//begin init
          //setBackground(Color.cyan);
          rainData = new Table();
          Label name = new Label("Enter number and click component");
          add(name);
          value = new TextField(10);
          add(value);
          value.addActionListener(this);
          addMouseListener(this);
     }//end init
     public void paint(Graphics g)
     {//begin paint
          rainData.display(g);
     }//end paint
     public void actionPerformed(ActionEvent event)
     {//begin ActionEvent
          newValue = Integer.parseInt(value.getText());
          rainData.setValue(newValue);          
          repaint();
     }//end ActionEvent
     public void mouseClicked(MouseEvent event)
     {//begin MouseEvent                              
          yCoord = event.getY();
          rainData.selectComponent(yCoord);          
          repaint();
     }//end MouseEvent
     public void mouseReleased(MouseEvent event)
     public void mousePressed(MouseEvent event)
     public void mouseEntered(MouseEvent event)
     public void mouseExited(MouseEvent event)
}//end class
class Table extends Rainfall
{//begin class Table
     private final int tableSize = 7;
     private int[] rain = new int[tableSize];
     private final int startX = 20;
     private final int startY = 40;
     private final int boxHeight = 20;
     private final int boxWidth = 40;
     public void display(Graphics g)
     {//begin display
          int y = startY;
          for(int day = 0; day < 7; day++)
          {//begin for
               g.drawRect(startX, y, boxWidth, boxHeight);
               g.drawString(Integer.toString(rain[day]),
                         startX, y + boxHeight * 3/4);
               y+=boxHeight;
          }//end for
          addValues();
          g.drawString("Total rainfall is " + sum, 100, 100);
     }//end display
     public void selectComponent(int y)
     {//begin selectComponent
          index = (y - startY)/boxHeight;
          rain[index] = newValue;          
     }//end selectComponent
     public void setValue(int value)
     {//begin setValue
          newValue = value;
     }//end setValue
     private void addValues()
     {//begin addValues
          sum = 0;
          for(int day = 0; day < 7; day++)
               sum=sum+rain[day];
     }//end addValues
}//end class Tables

Answer 1

....see this line: "addMouseListener(this);"
don't do that :)
you're capturing all the Applet's mouse events...not just the button