diff --git a/org/homelinux/largo/games/board/Board.java b/org/homelinux/largo/games/board/Board.java
--- a/org/homelinux/largo/games/board/Board.java
+++ b/org/homelinux/largo/games/board/Board.java
@@ -36,7 +36,7 @@
 	boolean black;
 	boolean blacksTurn;
 
-	MouseListener listener = null;
+	MouseListener listener;
 
 	/**
 	 * The init method initializes an empty board with a history.
@@ -276,8 +276,8 @@
 	 * Moves one half-move backward.
 	 */
 	public void backwards() {
-		History h1 = null;
-		History h2 = null;
+		History h1;
+		History h2;
 
 		if ( moveNr < 2)
 			return;
@@ -297,8 +297,8 @@
 	 * Moves one half-move forward.
 	 */
 	public void forward() {
-		History h1 = null;
-		History h2 = null;
+		History h1;
+		History h2;
 
 		if ( moveNr > stack.size()-2 )
 			return;
@@ -325,8 +325,8 @@
 	 * pop: undo the push operation.
 	 */
 	public void undo() {
-		History h1 = null;
-		History h2 = null;
+		History h1;
+		History h2;
 		int size = stack.size();
 
 		if ( size < 2 )