diff --git a/src/frames/IMainFrame.java b/src/frames/IMainFrame.java
new file mode 100644
index 0000000..678a2b1
--- /dev/null
+++ b/src/frames/IMainFrame.java
@@ -0,0 +1,10 @@
+package frames;
+
+import javax.swing.JPanel;
+
+// -------------------------------------------------------------------------
+//
+public interface IMainFrame {
+	void showMainPanel(JPanel nowPanel);
+	void showHistoryPanel(JPanel nowPanel, int index);
+}