Mine

import java.awt.*;import java.applet.*;import java.awt.event.*;public class SudokuBoard extends Applet{private Panel options;private Button easy,medium,hard,solve;private Panel sudokuGrid;private TextField[][] grid;public SudokuBoard(){options=new Panel();easy=new Button("Easy");medium=new Button("Medium");hard=new Button("Hard");solve=new Button("Solve");solve.setEnabled(false);easy.addActionListener(new EasyButtonListener());medium.addActionListener(new MediumButtonListener());hard.addActionListener(new HardButtonListener());solve.addActionListener(new SolveButtonListener());options.add(easy);options.add(medium);options.add(hard);options.add(solve);sudokuGrid=new Panel();sudokuGrid.setLayout(new GridLayout(9,9));grid=new TextField[9][9];for(int i=0;i<9;i++){for(int j=0;j<9;j++) {grid[i][j]=new TextField(1);sudokuGrid.add(grid[i][j]);}}add(options,BorderLayout.NORTH);add(sudokuGrid,BorderLayout.CENTER);}public class EasyButtonListener implements ActionListener{public void actionPerformed(ActionEvent event){grid[0][0].setText("1");grid[0][2].setText("3");grid[0][3].setText("5");grid[0][5].setText("8");grid[0][8].setText("9");grid[1][2].setText("8");grid[1][4].setText("4");grid[1][5].setText("7");grid[1][6].setText("6");grid[2][1].setText("4");grid[2][2].setText("7");grid[3][0].setText("2");grid[3][1].setText("7");grid[3][5].setText("3");grid[3][6].setText("4");grid[3][7].setText("9");grid[4][3].setText("9");grid[4][5].setText("2");grid[5][1].setText("5");grid[5][2].setText("9");grid[5][3].setText("6");grid[5][7].setText("2");grid[5][8].setText("1");grid[6][6].setText("2");grid[6][7].setText("7");grid[7][2].setText("2");grid[7][3].setText("4");grid[7][4].setText("9");grid[7][6].setText("8");grid[8][0].setText("3");grid[8][3].setText("7");grid[8][5].setText("1");grid[8][6].setText("9");grid[8][8].setText("4");solve.setEnabled(true);}}public class MediumButtonListener implements ActionListener{public void actionPerformed(ActionEvent event){solve.setEnabled(true);}}public class HardButtonListener implements ActionListener{public void actionPerformed(ActionEvent event){solve.setEnabled(true);}}public class SolveButtonListener implements ActionListener{public void actionPerformed(ActionEvent event){for(int i=0;i<9;i++){}}}}