diff --git a/src/main/java/dev/sillyangel/calc/Calculator.java b/src/main/java/dev/sillyangel/calc/Calculator.java
index 7ad8b46..d58f97c 100644
--- a/src/main/java/dev/sillyangel/calc/Calculator.java
+++ b/src/main/java/dev/sillyangel/calc/Calculator.java
@@ -37,15 +37,13 @@ public class Calculator extends JFrame implements KeyListener {
 	private static final String PREF_ALWAYS_ON_TOP = "alwaysOnTop";
 	public static final Preferences prefs = Preferences.userRoot().node(PREF_NODE_NAME);
 	public static String APPLICATION_VERSION = "1.0.0pre";
-	private JPanel contentPane;
-	private JTextField display;
+    private JTextField display;
 	private String operand1;
 	private String operator;
 	private String operand2;
 	protected boolean resultVisible;
 	protected double result;
-    private JComboBox<String> modeselect;
-	private final CalculatorHistory history;
+    private final CalculatorHistory history;
 	private final List<String> undoStack = new ArrayList<>();
 	private int undoIndex = -1;
 
@@ -113,11 +111,12 @@ public class Calculator extends JFrame implements KeyListener {
 		setFocusable(true);
 		addKeyListener(this);
 
-		contentPane = new JPanel();
+        JPanel contentPane = new JPanel();
 		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
 		setContentPane(contentPane);
 
 		display = new JTextField();
+		display.setFocusable(false);
 		display.setEditable(false);
 		display.setFont(new Font("Segoe UI", Font.PLAIN, 22));
 		display.setColumns(10);
@@ -194,7 +193,12 @@ public class Calculator extends JFrame implements KeyListener {
 		JMenuItem preferencesm = new JMenuItem("Preferences");
 		preferencesm.setMnemonic('P');
 		preferencesm.addActionListener(e -> PreferencesAction());
-		
+		undo.addActionListener(e -> undoAction());
+		redo.addActionListener(e -> redoAction());
+		cut.addActionListener(e -> cutAction());
+		copy.addActionListener(e -> copyAction());
+		paste.addActionListener(e -> pasteAction());
+
 		edit.add(undo);
 		edit.add(redo);
 		edit.add(cut);
@@ -214,7 +218,7 @@ public class Calculator extends JFrame implements KeyListener {
 		setJMenuBar(menubar);
 
         String[] modes = new String[]{"Standard", "Scientific", "Data calculation"};
-        modeselect = new JComboBox<>(modes);
+        JComboBox<String> modeselect = new JComboBox<>(modes);
 		modeselect.addActionListener(new ActionListener() {
 			@SuppressWarnings("unchecked")
 			public void actionPerformed(ActionEvent e) {