formatting and compiling

Display.java

@@ -1,23 +1,24 @@
 import javax.swing.*;
 
 public class Display {
-    public static void main(String[] args) throws Exception{
-        //creating instance of JFrame
-        int boardWidth = 400;
-        int boardHeight = 400;
-        
-        JFrame game = new JFrame();
-        game.setSize(boardWidth, boardHeight);
-        game.setVisible(true); 
-        game.setLocationRelativeTo(null);
-        game.setResizable(false);
-        
-        Chess chess = new Chess(boardWidth, boardHeight);
-        game.add(chess);
-        game.pack();
-        chess.requestFocus();
-    }
+  public static void main(String[] args) throws Exception {
+    // creating instance of JFrame
+    int boardWidth = 400;
+    int boardHeight = 400;
+
+    JFrame game = new JFrame();
+    game.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+    game.setSize(boardWidth, boardHeight);
+    game.setVisible(true);
+    game.setLocationRelativeTo(null);
+    game.setResizable(false);
+
+    Chess chess = new Chess(boardWidth, boardHeight);
+    game.add(chess);
+    game.pack();
+    chess.requestFocus();
+  }
 }
 
-
-//images : https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQN6qOyhiUDLlTlwl19PaMTeiY5rSOqkUqu-g&s
+// images :
+// https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQN6qOyhiUDLlTlwl19PaMTeiY5rSOqkUqu-g&s