diff --git a/src/Main.java b/src/Main.java
index 2dce076..5d49e85 100644
--- a/src/Main.java
+++ b/src/Main.java
@@ -10,5 +10,6 @@
 
 		// generate window
 		JFrame mainFrame = new MainFrame();
+		mainFrame.setVisible(true);
 	}
 }
diff --git a/src/frames/MainFrame.java b/src/frames/MainFrame.java
index 56a61cb..25199bd 100644
--- a/src/frames/MainFrame.java
+++ b/src/frames/MainFrame.java
@@ -28,7 +28,6 @@
 	public MainFrame() {
 		super("POS");
 
-		this.setTitle("POS");
 		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
 		// initialize model
@@ -45,32 +44,8 @@
 		mainPanel.setVisible(true);
 		this.add(mainPanel, BorderLayout.CENTER);
 		
-		// set current panel
-		curPanel = mainPanel;
-		
 		// adjust window size
 		this.pack();
-		this.setVisible(true);
-	}
-
-	// -------------------------------------------------------------------------
-	// -------------------------------------------------------------------------
-	// public
-	// -------------------------------------------------------------------------
-	//
-	public void reloadPanel(String destinationPanelName) {
-		// main
-		if (destinationPanelName.equals(State.MAIN)) {
-			this.remove(this.mainPanel);
-			MainPanel mainPanel = new MainPanel(this, model);
-			this.add(mainPanel);
-		}
-		// history
-		else if (destinationPanelName.equals(State.DETAIL)) {
-			this.remove(this.historyPanel);
-			ShowHistoryPanel historyPanel = new ShowHistoryPanel(this, model);
-			this.add(historyPanel);
-		}
 	}
 
 	// -------------------------------------------------------------------------
diff --git a/src/frames/State.java b/src/frames/State.java
deleted file mode 100644
index 0d4ad4d..0000000
--- a/src/frames/State.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package frames;
-
-// -------------------------------------------------------------------------
-//
-public class State {
-	public static String MAIN = "Main";
-	public static String DETAIL = "Detail";
-}