help

Using jGrasp and the Software Development Kit, write a program in response to the following prompt:

Design a GUI program to find the weighted average of four test scores. The four test scores and their respective weights are given in the following format:

testscore1 weight1
...

For example, the sample data is as follows:

75 0.20
95 0.35
85 0.15
65 0.30

The user is supposed to enter the data and press a Calculate button. The program must display the weighted average.

Remember to follow proper form and design in your response.

this is what i came up with but get the errors 

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

import java.text.DecimalFormat;

import java.util.Scanner;

public class TestScores 

extends JFrame

75 0.20

95 0.35

85 0.15

65 0.30 

{

   private JLabel blankoneL, blanktwoL, blankthreeL,scoreL, weightL, oneL, twoL, threeL, fourL, averageL;

   private JTextField oneTF, twoTF, threeTF, fourTF, woneTF, wtwoTF, wthreeTF, wfourTF, averageTF;

   private JButton calculateB,exitB;

   private CalculateButtonHandler cbHandler;

   private ExitButtonHandler ebHandler;

   private static final int WIDTH =600;

   private static final int HEIGHT=400;

   public TestScores()

   //Making labels for the GUI

   {

      blankoneL=new JLabel ("");

      blanktwoL=new JLabel("");

      blankthreeL=new JLabel("");

      scoreL=new JLabel ("Score",SwingConstants.CENTER);

      weightL=new JLabel ("weight", SwingConstants.CENTER);

      oneL=new JLabel("Test score #1:",SwingConstants.RIGHT);

      twoL=new JLabel ("Test score #2:" ,SwingConstants.RIGHT);

      threeL=new JLabel ("Test score #3:",SwingConstants.RIGHT);

      fourL=new JLabel ("Test score #4:",SwingConstants.RIGHT);

      averageL=new JLabel ("Test score average:" ,SwingConstants.RIGHT);

    //Making user input fields

      oneTF=new JTextField(5);

      twoTF=new JTextField(5);

      threeTF= new JTextField(5);

      fourTF= new JTextField(5);

      woneTF= new JTextField(5);

      wtwoTF= new JTextField(5);

      wthreeTF= new JTextField(5);

      wfourTF= new JTextField(5);

      averageTF= new JTextField(5);

    //Making a CTA button to get the average

      calculateB= new JButton("Calculate");

      cbHandler=new CalculateButtonHandler();

      calculateB.addActionListener(cbHandler);

    //Making an exit button

      exitB=new JButton("Exit Program");

      ebHandler=new ExitButtonHandler();

      exitB.addActionListener(ebHandler);

      setTitle ("Weighted Average Test Scores");

      Container pane = getContentPane();

      pane.setLayout(new GridLayout(7,3));

      pane.add(blankoneL);

      pane.add(scoreL);

      pane.add (weightL);

      pane.add (oneL);

      pane.add (oneTF);

      pane.add (woneTF);

      pane.add (twoL);

      pane.add (twoTF);

      pane.add (wtwoTF);

      pane.add (threeL);

      pane.add (threeTF);

      pane.add (wthreeTF);

      pane.add (fourL);

      pane.add (fourTF);

      pane.add (wfourTF);

      pane.add (averageL);

      pane.add (averageTF);

      pane.add (blanktwoL);

      pane.add (calculateB);

      pane.add (blankthreeL);

      pane.add (exitB);

      setSize(WIDTH,HEIGHT);

      setVisible(true);

      setDefaultCloseOperation(EXIT_ON_CLOSE);

   }

   private class CalculateButtonHandler implements ActionListener{

      public void actionPerformed(ActionEvent e)

      {

         double one, wone, two,wtwo, three, wthree,four,wfour, ave;

         DecimalFormat twoDigits=new DecimalFormat("0.00");

         one=Double.parseDouble(oneTF.getText());

         wone=Double.parseDouble(woneTF.getText());

         two=Double.parseDouble(twoTF.getText());

         wtwo=Double.parseDouble (wtwoTF.getText());

         three=Double.parseDouble (threeTF.getText());

         wthree=Double.parseDouble (wthreeTF.getText());

         four=Double.parseDouble (fourTF.getText());

         wfour=Double.parseDouble (wfourTF.getText());

         ave=(one*wone+two*wtwo+three*wthree+four*wfour)/(wone+wtwo+wthree+wfour);

         averageTF.setText(""+twoDigits.format(ave));

             }

    }

    private class ExitButtonHandler implements ActionListener {

        public void actionPerformed(ActionEvent e) {

        }

    }

}

         this is the error

 ----jGRASP exec: javac -g TestScores.java

TestScores.java:14: error: '{' expected

extends JFrame

              ^

1 error

 ----jGRASP wedge2: exit code for process is 1.

 ----jGRASP: operation complete.