Help with Linking a scrollbar to a textfield

I have been asked to create a small application in java that does the following. On a frame there are 3 types of object - canvas, scrollbar and textfield.  In the textfield the range of numbers will be 0 - 255 If the scrollbar(there are three - red green and blue) is moved the numbers in the corresponding textfield(three also red,green,blue) will change and the canvas will fill with more of or less of that particular color.

All that I have left to do is the textfield part, ie if you put in a number in the textfield it must change the position of the scrollbar and the color of the canvas,  

Below is the code I have so far, (the listeners are the area I need to update).  
Does anyone have any ideas how to go about it??

Thanks R79

package Colourchooser;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;




public class Colourchooser extends JFrame implements ActionListener,AdjustmentListener{

    // Variable declarations of textfields and scrollbars.
    JTextField redtfield,greentfield,bluetfield;  
    Container contentpane;  
    JLabel redlabel,greenlabel,bluelabel;
    Scrollbar scrollr,scrollg,scrollb;  
    GridLayout colourlayout;  
    int redValue, greenValue, blueValue;

    // Variable declaration of DrawCanvas
    DrawCanvas c;

    public Colourchooser() {    
        //define and set the layout used
        contentpane = getContentPane () ;
        setTitle ( "Colour Chooser" ) ;
        setBackground(Color.gray);
        setSize(1000,500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        colourlayout = new GridLayout(0,10);
        contentpane.setLayout(colourlayout);
     
        // - define the scrollbars, labels and textfields used
        redtfield = new JTextField(redValue);  
        greentfield = new JTextField(greenValue);
        bluetfield = new JTextField(blueValue);  
        redlabel = new JLabel("Red");  
        greenlabel = new JLabel("Green");  
        bluelabel = new JLabel("Blue");
        scrollr = new Scrollbar(Scrollbar.VERTICAL, 0,1, 0, 255);
        scrollg = new Scrollbar(Scrollbar.VERTICAL, 0,1, 0, 255);  
        scrollb = new Scrollbar(Scrollbar.VERTICAL, 0,1, 0, 255);
        // - Setting value of DrawCanvas to null - If this wass'nt here
        // - when the program executed it threw NullPointerExceptions
        c = new DrawCanvas();                                                  
       
        //  - add the scrollbars, labels and textfields to the layout
        contentpane.add(redlabel);  
        contentpane.add(scrollr);  
        contentpane.add(redtfield);
        contentpane.add(greenlabel);
        contentpane.add(scrollg);  
        contentpane.add(greentfield);  
        contentpane.add(bluelabel);  
        contentpane.add(scrollb);  
        contentpane.add(bluetfield);
           
        //    - add the instance (i.e. c) to your layout
        contentpane.add(c);
     
        //    - add the action and adjustment listeners
        scrollr.addAdjustmentListener(new AdjustmentlistenerS());  
        scrollb.addAdjustmentListener(new AdjustmentlistenerS());
        scrollg.addAdjustmentListener(new AdjustmentlistenerS());
        pack();  
        show();
    } // end of the constructor


    public static void main(String args[]){

      new Colourchooser();

    }

    public void actionPerformed(ActionEvent e){

      // In this method, retrieve the red, green and blue
      // values entered into the textfields.
       

      // You also need to set the value in the corresponding scrollbar to be
      // the same value as the textfield value.

      // Call the setCanvasColour method (in the DrawCanvas class) to set the
      // colour of the canvas to the new values i.e.
      //c.setCanvasColor(redtfield, greenValue, blueValue);

    }

    public void adjustmentValueChanged(AdjustmentEvent e) {
    }    
   
   
         class AdjustmentlistenerS implements AdjustmentListener {

         public void adjustmentValueChanged(AdjustmentEvent e){

      // In this method, retrieve the red, green and blue
      // values entered into the textfields.
      redtfield.getText();
      bluetfield.getText();
      greentfield.getText();
                 
      // You also need to set the value in the corresponding textfield to be
      // the same value as the scrollbar value.

      // Call the setCanvasColour method (in the DrawCanvas class) to set the
      // colour of the canvas to the new values i.e.

      c.setCanvasColor(scrollr.getValue(),scrollg.getValue(),scrollb.getValue());

   }

}}


********************************************************************************DrawCanvas.java

package Colourchooser;


import java.awt.* ;


public class DrawCanvas extends Canvas



{
     // Variable declarations
         int greenValue, redValue, blueValue;
     
       
 
   

     public DrawCanvas()
     {
         // set the size of the canvas
              setSize(65,65);
     }

    public void paintComponent(Graphics g)

     {
        // set the colour of the canvas
              g.setColor(getBackground());
              g.fillRect(0, 0, getWidth(), getHeight());

     }

     public void setCanvasColor(int red, int green, int blue)
     {
        // "repaint" the canvas(this will call the paint method)
                 setBackground(new Color(red, green, blue));
                 repaint();
     }

}