diff --git a/item.lua b/item.lua
index 770e29a..b96249f 100644
--- a/item.lua
+++ b/item.lua
@@ -27,7 +27,6 @@ function m:itemMode()
     self.mousepressed = window.mousepressed(function (self, x, y, button)
         log:info(self)
         inventory.selected_item = self
-        log:format("selected idx : %s", inventory.selected_item.idx)
     end)
 end
 
diff --git a/main.lua b/main.lua
index 784951a..61a4f91 100644
--- a/main.lua
+++ b/main.lua
@@ -17,15 +17,17 @@ end
 --load room list
 local rooms = require("rooms")
 
-current_room = rooms['default']
+current_room = rooms['Alley']
 
 function set_room_raw(r)
+    current_room:onexit()
     current_room = r
+    current_room:onenter()
 end
 
 function set_room(r)
-    current_room = rooms[r]
-    assert(current_room)
+    assert(rooms[r])
+    set_room_raw(rooms[r])
 end
 
 screen = {
@@ -64,7 +66,7 @@ end)
 
 inventory.draw = window.draw(function (self)
     for i, item in pairs(self.items) do
-        if self.selected_item and self.selected_item.idx == i then
+        if self.selected_item and self.selected_item == item then
             love.graphics.circle('line', 60*i - 30, 30, 25)
         end
 
@@ -83,7 +85,7 @@ end
 
 function inventory:pickup(item)
     util.add_entity(self.items, item)
-    self:set_pos(item.idx, item)
+    self:set_pos(item.idx[self.items], item)
 end
 
 function inventory:drop(item)
diff --git a/obj/door.lua b/obj/door.lua
index d0c1d73..a820d26 100644
--- a/obj/door.lua
+++ b/obj/door.lua
@@ -27,37 +27,41 @@ function m:draw()
     end
 end
 
-m.keyMode = window.mousepressed(function (self)
-    if self.locked then
-        local i = inventory.selected_item
-        if i and i.code then
-            if i.code == self.code then
-                self.locked = false
-                inventory:use()
-                
-                log:log("Door opened.")
+function m:keyMode()
+    self.mousepressed = window.mousepressed(function (self)
+        if self.locked then
+            local i = inventory.selected_item
+            if i and i.code then
+                if i.code == self.code then
+                    self.locked = false
+                    inventory:use()
+
+                    log:log("Door opened.")
+                else
+                    log:log("This seems not a matching key.")
+                    inventory.selected_item = nil
+                end
             else
-                log:log("This seems not a matching key.")
-                inventory.selected_item = nil
+                log:log("It's locked.")
             end
         else
-            log:log("It's locked.")
+            log:format("You enter %s", self.destination)
+            set_room(self.destination)
         end
-    else
-        log:format("You enter %s", self.destination)
-        set_room(self.destination)
-    end
-end)
+    end)
+end
 
-m.keypadMode = window.mousepressed(function (self)
-    if self.locked then
-        log:log("It's locked.")
-    else
-        log:format("You enter %s", self.destination)
-        set_room(self.destination)
-    end
-end)
+function m:keypadMode()
+    self.mousepressed = window.mousepressed(function (self)
+        if self.locked then
+            log:log("It's locked.")
+        else
+            log:format("You enter %s", self.destination)
+            set_room(self.destination)
+        end
+    end)
+end
 
-m.mousepressed = m.keyMode
+m:keyMode()
 
 return m
diff --git a/obj/keypad.lua b/obj/keypad.lua
index 08461a3..165a3c4 100644
--- a/obj/keypad.lua
+++ b/obj/keypad.lua
@@ -3,9 +3,13 @@ local entity = require('entity')
 local keypad = require('room/keypad')
 
 local m = entity:from{
-    width = 50,
-    height = 50,
-    lines = {'fill', {0, 0, 0, 50, 50, 50, 50, 0}},
+    width = 30,
+    height = 40,
+    lines = {
+        {'fill', {0, 0, 0, 40, 30, 40, 30, 0}},
+        {'fill', {5, 5, 25, 5, 25, 10, 5, 10}},
+        {'fill', {5, 15, 25, 15, 25, 35, 5, 35}},
+    },
     code = 45100,
 }
 
diff --git a/room.lua b/room.lua
index 45717a2..c4156be 100644
--- a/room.lua
+++ b/room.lua
@@ -26,14 +26,6 @@ function room:from(t)
     return r
 end
 
-function room:insert(obj)
-    util.add_entity(self.objects, obj)
-end
-
-function room:remove(obj)
-    util.del_entity(self.objects, obj)
-end
-
 room.mousepressed = window.propagate{'edges', 'objects'}
 
 function room:draw()
@@ -48,6 +40,27 @@ function room:draw()
     end
 end
 
+function room:insert(obj)
+    util.add_entity(self.objects, obj)
+end
+
+function room:remove(obj)
+    util.del_entity(self.objects, obj)
+end
+
+
+function room:onenter()
+    if self.update then
+        register(self)
+    end
+end
+
+function room:onexit()
+    if self.update then
+        unregister(self)
+    end
+end
+
 function room.calc_align(width, height)
     local sx = (320 - width)/2
     local sy = (240 - height)/2
diff --git a/room/alley.lua b/room/alley.lua
index 65bcae2..38ee45f 100644
--- a/room/alley.lua
+++ b/room/alley.lua
@@ -3,7 +3,7 @@ local edge = require("edge")
 
 local m = room:new()
 
-edge.set(m, 'down', "sundial_alley")
+edge.set(m, 'down', "Sundial alley")
 --edge.set(m, 'left', "alley2")
 
 return m
diff --git a/room/keypad.lua b/room/keypad.lua
index 509998c..5f78f03 100644
--- a/room/keypad.lua
+++ b/room/keypad.lua
@@ -55,8 +55,6 @@ function m:from(t)
 
     edge.set(kp, "down", kp.room)
 
-    register(kp)
-
     return kp
 end
 
diff --git a/room/sundial_alley.lua b/room/sundial_alley.lua
index 8a3d506..c1cf425 100644
--- a/room/sundial_alley.lua
+++ b/room/sundial_alley.lua
@@ -22,8 +22,8 @@ keypad:from{
     oncorrect = function (self)
         d.locked = false
     end,
-}:install(m, 180, 100)
+}:install(m, 160, 90)
 
-edge.set(m, 'up', "alley")
+edge.set(m, 'up', "Alley")
 
 return m
diff --git a/rooms.lua b/rooms.lua
index 53199f0..0e8c044 100644
--- a/rooms.lua
+++ b/rooms.lua
@@ -1,8 +1,8 @@
 local m = {
     ['default'] = require('room/default'),
     ['doortest'] = require('room/doortest'),
-    ['alley'] = require("room/alley"),
-    ['sundial_alley'] = require("room/sundial_alley"),
+    ['Alley'] = require("room/alley"),
+    ['Sundial alley'] = require("room/sundial_alley"),
 }
 
 return m
diff --git a/util.lua b/util.lua
index fd49ede..72d9744 100644
--- a/util.lua
+++ b/util.lua
@@ -23,14 +23,17 @@ end
 
 function m.add_entity(a, x)
     table.insert(a, x)
-    x.idx = #a
+    if not x.idx then
+        x.idx = {}
+    end
+    x.idx[a] = #a
 end
 
 function m.del_entity(a, x)
-    table.remove(a, x.idx)
+    table.remove(a, x.idx[a])
 
     for i, v in ipairs(a) do
-        v.idx = i
+        v.idx[a] = i
     end
 end