-        win.SetDefaultSize((120, 1000))
-        win.SetOrientation(wx.LAYOUT_VERTICAL)
-        win.SetAlignment(wx.LAYOUT_LEFT)
-        win.SetBackgroundColour(wx.Colour(0, 255, 255))
-        win.SetSashVisible(wx.SASH_RIGHT, True)
+        leftwin2.SetDefaultSize((120, 1000))
+        leftwin2.SetOrientation(wx.LAYOUT_VERTICAL)
+        leftwin2.SetAlignment(wx.LAYOUT_LEFT)
+        leftwin2.SetBackgroundColour(wx.Colour(0, 255, 255))
+        leftwin2.SetSashVisible(wx.SASH_RIGHT, True)
+
+        self.leftWindow2 = leftwin2
+        winids.append(leftwin2.GetId())
+
+        # will occupy the space not used by the Layout Algorithm
+        self.remainingSpace = wx.Panel(self, -1, style=wx.SUNKEN_BORDER)
+
+        self.Bind(
+            wx.EVT_SASH_DRAGGED_RANGE, self.OnSashDrag,
+            id=min(winids), id2=max(winids)
+            )