diff --git a/src/main/java/envoy/client/ui/LoginDialog.java b/src/main/java/envoy/client/ui/LoginDialog.java
new file mode 100644
index 0000000..db88176
--- /dev/null
+++ b/src/main/java/envoy/client/ui/LoginDialog.java
@@ -0,0 +1,118 @@
+package envoy.client.ui;
+
+import java.awt.*;
+import java.security.NoSuchAlgorithmException;
+
+import javax.swing.*;
+import javax.swing.border.EmptyBorder;
+
+import envoy.data.LoginCredentials;
+
+/**
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>LoginDialog.java</strong><br>
+ * Created: <strong>01.01.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy v0.3-alpha
+ */
+public class LoginDialog extends JDialog {
+
+	private final JPanel contentPanel = new JPanel();
+
+	private static final long	serialVersionUID	= 352021600833907468L;
+	private JTextField			textField;
+	private JPasswordField		passwordField;
+
+	private LoginCredentials credentials;
+
+	/**
+	 * Displays a dialog enabling the user to enter their user name and password.
+	 * 
+	 * @since Envoy v0.3-alpha
+	 */
+	public LoginDialog() {
+		setSize(338, 123);
+		setLocationRelativeTo(null);
+		getContentPane().setLayout(new BorderLayout());
+		contentPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
+		getContentPane().add(contentPanel, BorderLayout.CENTER);
+		GridBagLayout gbl_contentPanel = new GridBagLayout();
+		gbl_contentPanel.columnWidths	= new int[] { 0, 0, 0 };
+		gbl_contentPanel.rowHeights		= new int[] { 0, 0, 0 };
+		gbl_contentPanel.columnWeights	= new double[] { 0.0, 1.0, Double.MIN_VALUE };
+		gbl_contentPanel.rowWeights		= new double[] { 0.0, 0.0, Double.MIN_VALUE };
+		contentPanel.setLayout(gbl_contentPanel);
+		{
+			JLabel				lblUserName		= new JLabel("User name:");
+			GridBagConstraints	gbc_lblUserName	= new GridBagConstraints();
+			gbc_lblUserName.anchor	= GridBagConstraints.EAST;
+			gbc_lblUserName.insets	= new Insets(0, 0, 5, 5);
+			gbc_lblUserName.gridx	= 0;
+			gbc_lblUserName.gridy	= 0;
+			contentPanel.add(lblUserName, gbc_lblUserName);
+		}
+		{
+			textField = new JTextField();
+			GridBagConstraints gbc_textField = new GridBagConstraints();
+			gbc_textField.insets	= new Insets(0, 0, 5, 0);
+			gbc_textField.fill		= GridBagConstraints.HORIZONTAL;
+			gbc_textField.gridx		= 1;
+			gbc_textField.gridy		= 0;
+			contentPanel.add(textField, gbc_textField);
+			textField.setColumns(10);
+		}
+		{
+			JLabel				lblPassword		= new JLabel("Password:");
+			GridBagConstraints	gbc_lblPassword	= new GridBagConstraints();
+			gbc_lblPassword.anchor	= GridBagConstraints.EAST;
+			gbc_lblPassword.insets	= new Insets(0, 0, 0, 5);
+			gbc_lblPassword.gridx	= 0;
+			gbc_lblPassword.gridy	= 1;
+			contentPanel.add(lblPassword, gbc_lblPassword);
+		}
+		{
+			passwordField = new JPasswordField();
+			GridBagConstraints gbc_passwordField = new GridBagConstraints();
+			gbc_passwordField.fill	= GridBagConstraints.HORIZONTAL;
+			gbc_passwordField.gridx	= 1;
+			gbc_passwordField.gridy	= 1;
+			contentPanel.add(passwordField, gbc_passwordField);
+		}
+		{
+			JPanel buttonPane = new JPanel();
+			buttonPane.setLayout(new FlowLayout(FlowLayout.RIGHT));
+			getContentPane().add(buttonPane, BorderLayout.SOUTH);
+			{
+				JButton okButton = new JButton("OK");
+				okButton.addActionListener((evt) -> {
+					try {
+						credentials = new LoginCredentials(textField.getText(), passwordField.getPassword());
+						dispose();
+					} catch (NoSuchAlgorithmException e) {
+						e.printStackTrace();
+					}
+				});
+				okButton.setActionCommand("OK");
+				buttonPane.add(okButton);
+				getRootPane().setDefaultButton(okButton);
+			}
+			{
+				JButton cancelButton = new JButton("Cancel");
+				cancelButton.addActionListener((evt) -> dispose());
+				cancelButton.setActionCommand("Cancel");
+				buttonPane.add(cancelButton);
+			}
+		}
+
+		setModal(true);
+		setVisible(true);
+	}
+
+	/**
+	 * @return the {@link LoginCredentials} entered by the user, or {@code null} if
+	 *         the dialog has been cancelled
+	 * @since Envoy v0.3-alpha
+	 */
+	public LoginCredentials getCredentials() { return credentials; }
+}
\ No newline at end of file
diff --git a/src/main/java/envoy/client/ui/Startup.java b/src/main/java/envoy/client/ui/Startup.java
index ae01e82..3e4692d 100644
--- a/src/main/java/envoy/client/ui/Startup.java
+++ b/src/main/java/envoy/client/ui/Startup.java
@@ -71,15 +71,13 @@ public class Startup {
 		EnvoyLog.setFileLevelBarrier(config.getFileLevelBarrier());
 		EnvoyLog.setConsoleLevelBarrier(config.getConsoleLevelBarrier());
 
-		// Ask the user for their user name
-		String userName = JOptionPane.showInputDialog("Please enter your username");
-		if (userName == null || userName.isEmpty()) {
-			logger.severe("User name is not set or empty. Exiting...");
-			System.exit(1);
-		}
+		// Ask the user for their user name and password
+		LoginCredentials credentials = new LoginDialog().getCredentials();
 
-		// TODO: create dialog
-		String pass = JOptionPane.showInputDialog("Enter password");
+		if (credentials == null) {
+			logger.info("The login process has been aborted by the user. Exiting...");
+			System.exit(0);
+		}
 
 		// Initialize the local database
 		LocalDB localDB;
@@ -99,18 +97,18 @@ public class Startup {
 		Client client = new Client();
 		try {
 			// Try entering online mode first
-			client.onlineInit(new LoginCredentials(userName, pass.toCharArray()));
+			client.onlineInit(credentials);
 		} catch (Exception e1) {
 			logger.warning("Could not connect to server. Trying offline mode...");
 			e1.printStackTrace();
 			try {
 				// Try entering offline mode
 				localDB.loadUsers();
-				User clientUser = localDB.getUsers().get(userName);
+				User clientUser = localDB.getUsers().get(credentials.getName());
 				if (clientUser == null) throw new EnvoyException("Could not enter offline mode: user name unknown");
 				client.setSender(clientUser);
 				JOptionPane.showMessageDialog(null,
-						"A connection to the server could not be established. Starting in offline mode.",
+						"A connection to the server could not be established. Starting in offline mode.\n" + e1,
 						"Connection error",
 						JOptionPane.WARNING_MESSAGE);
 			} catch (Exception e2) {
@@ -132,7 +130,7 @@ public class Startup {
 		} catch (Exception e) {
 			e.printStackTrace();
 			JOptionPane.showMessageDialog(null,
-					"Error while loading local database: " + e.toString() + "\nChats might not be stored locally.",
+					"Error while loading local database: " + e + "\nChats might not be stored locally.",
 					"Local DB error",
 					JOptionPane.WARNING_MESSAGE);
 		}