private void Solve_Click(object sender, EventArgs e)
 {
     SUDOKU.Solve();
 }
 private void Clear_Click(object sender, EventArgs e)
 {
     this.Controls.Remove(sudoku);
     sudoku.Dispose();
     sudoku = new SUDOKU(this);
 }
 public Form1()
 {
     InitializeComponent();
     sudoku = new SUDOKU(this);
 }