diff --git a/examples/advance       supported concepts for all supported P system/dissolve.txt b/examples/advance       supported concepts for all supported P system/dissolve.txt
index 6d94f94..3e47e04 100644
--- a/examples/advance       supported concepts for all supported P system/dissolve.txt	
+++ b/examples/advance       supported concepts for all supported P system/dissolve.txt	
@@ -1,15 +1,15 @@
-Environment{
-	Membrane a{
-		Object b,c,d,e;
-		Rule r1= b -> dissolve;
-		Rule r2= c -> (a, in b);
-		
-		Membrane b{
-			Object f;
-		}
-		
-		Membrane c{
-		
-		}
-	}
+Environment{
+	Membrane a{
+		Object b,c,d,e;
+		Rule r1= b -> dissolve;
+		Rule r2= c -> (a, in b);
+		
+		Membrane b{
+			Object f;
+		}
+		
+		Membrane c{
+		
+		}
+	}
 }
\ No newline at end of file
diff --git a/src/upsimulator/gui/MainWindow.java b/src/upsimulator/gui/MainWindow.java
index 23075da..141c059 100644
--- a/src/upsimulator/gui/MainWindow.java
+++ b/src/upsimulator/gui/MainWindow.java
@@ -337,7 +337,7 @@ public MainWindow() {
 	private void initialize() {
 		frmUpsimulator = new JFrame();
 		frmUpsimulator.setTitle("UPSimulator\r\n");
-		frmUpsimulator.setBounds(100, 100, 894, 811);
+		frmUpsimulator.setBounds(100, 100, 998, 811);
 		frmUpsimulator.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
 		frmUpsimulator.getContentPane().setLayout(new BorderLayout(0, 0));
 		frmUpsimulator.addWindowListener(new WindowListener() {
@@ -440,6 +440,7 @@ public void actionPerformed(ActionEvent e) {
 		projectPanel.add(separator_1, gbc_separator_1);
 
 		splitPane = new JSplitPane();
+		splitPane.setResizeWeight(0.5);
 		splitPane.setToolTipText("");
 		splitPane.setOneTouchExpandable(true);
 		GridBagConstraints gbc_splitPane = new GridBagConstraints();
@@ -450,12 +451,14 @@ public void actionPerformed(ActionEvent e) {
 		splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT);
 
 		JPanel panel = new JPanel();
-		panel.setBorder(null);
+		panel.setBorder(new TitledBorder(null, "Membrane Classes", TitledBorder.LEADING, TitledBorder.TOP, null, null));
 		panel.setBackground(UIManager.getColor("Button.background"));
 		splitPane.setLeftComponent(panel);
 		panel.setLayout(new BorderLayout(0, 0));
 
 		modelFileJList = new JList<>();
+		modelFileJList.setBackground(new Color(255, 255, 255));
+		modelFileJList.setBorder(null);
 		modelFileJList.addMouseListener(new MouseAdapter() {
 			@Override
 			public void mouseClicked(MouseEvent e) {