add screenshots

src/main/java/dcccontroller/ErrorManager.java

@@ -0,0 +1,12 @@
+package dcccontroller;
+
+import javax.swing.*;
+
+public class ErrorManager {
+
+    static public void showErrorMessage(String title, String msg) {
+        SwingUtilities.invokeLater(() -> {
+            JOptionPane.showMessageDialog(null, msg, title, JOptionPane.ERROR_MESSAGE);
+        });
+    }
+}

src/main/java/dcccontroller/configuration/ConfigurationManager.java

@@ -1,6 +1,7 @@
 package dcccontroller.configuration;
 
 
+import dcccontroller.ErrorManager;
 import dcccontroller.configuration.csv.CSVFileHandler;
 import dcccontroller.model.CPFunctionItem;
 import dcccontroller.util.Change;
@@ -151,9 +152,7 @@ private HashMap<String, String> mapRowValues(String line) {
     }
 
     private void showErrorMessage(Exception e) {
-        SwingUtilities.invokeLater(() -> {
-            JOptionPane.showMessageDialog(null, "Could not open file \n" + e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
-        });
+        ErrorManager.showErrorMessage("Configuration Error", "Could not open file \n" + e.getMessage());
     }
 
     private String createConfigName(File file) {

src/main/java/dcccontroller/serial/SerialCommunicationHelper.java

@@ -1,6 +1,7 @@
 package dcccontroller.serial;
 
 import com.fazecast.jSerialComm.SerialPort;
+import dcccontroller.ErrorManager;
 import dcccontroller.util.Change;
 
 import java.io.InputStream;
@@ -121,7 +122,7 @@ private void sendMessage(String message) {
             }
             listenForMessages(3);
         } else {
-            System.out.println("Port busy!");
+            ErrorManager.showErrorMessage("Connection Error", "Port busy!");
         }
     }