diff --git a/src/core/lcurses/lcurses.c b/src/core/lcurses/lcurses.c
index 1e8f7e1..1dbf340 100644
--- a/src/core/lcurses/lcurses.c
+++ b/src/core/lcurses/lcurses.c
@@ -2313,7 +2313,7 @@ static const luaL_Reg curseslib[] =
     {NULL, NULL}
 };
 
-__export int luaopen_ltui_curses (lua_State *L)
+__export int luaopen_ltui_lcurses (lua_State *L)
 {
     /*
     ** create new metatable for window objects
diff --git a/src/ltui/base/os.lua b/src/ltui/base/os.lua
index 9f958ff..51800c8 100644
--- a/src/ltui/base/os.lua
+++ b/src/ltui/base/os.lua
@@ -26,7 +26,16 @@
 local os = os or {}
 
 -- load modules
-local string    = require("ltui/base/string")
+local string = require("ltui/base/string")
+
+-- is file?
+function os.isfile(filepath)
+    local file = filepath and io.open(filepath, 'r') or nil
+    if file then
+        file:close()
+    end
+    return file ~= nil
+end
 
 -- raise an exception and abort the current script
 --
diff --git a/src/ltui/base/string.lua b/src/ltui/base/string.lua
index abf92e9..12691ad 100644
--- a/src/ltui/base/string.lua
+++ b/src/ltui/base/string.lua
@@ -25,6 +25,11 @@
 -- define module: string
 local string = string or {}
 
+-- match the start string
+function string:startswith(str) 
+    return self:find('^' .. str) ~= nil
+end
+
 -- find the last substring with the given pattern
 function string:find_last(pattern, plain)
 
diff --git a/src/ltui/curses.lua b/src/ltui/curses.lua
index 6885471..28b9425 100644
--- a/src/ltui/curses.lua
+++ b/src/ltui/curses.lua
@@ -28,7 +28,7 @@ $Id: core.lua 18 2007-06-21 20:43:52Z tngd $
 --------------------------------------------------------------------------]]
 
 -- load modules
-local curses = require("ltui.curses")
+local curses = require("ltui.lcurses")
 local os     = require("ltui/base/os")
 local log    = require("ltui/base/log")
 
diff --git a/tests/load.lua b/tests/load.lua
index 29bbb73..d860d81 100755
--- a/tests/load.lua
+++ b/tests/load.lua
@@ -6,4 +6,58 @@ local os     = require("ltui/base/os")
 local ltui   = require("ltui.curses")
 print(ltui)
 
-print(os.host())
+--  requires
+local log  = require("ltui/base/log")
+local rect = require("ltui/rect")
+local view = require("ltui/view")
+local label = require("ltui/label")
+local event = require("ltui/event")
+local button = require("ltui/button")
+local application = require("ltui/application")
+
+-- the demo application
+local demo = application()
+
+-- init demo
+function demo:init()
+
+    -- init name 
+    application.init(self, "demo")
+
+    -- show desktop, menubar and statusbar
+    self:insert(self:desktop())
+    self:insert(self:menubar())
+    self:insert(self:statusbar())
+
+    -- init title
+    self:menubar():title():text_set("Menu Bar (Hello)")
+
+    -- add title label
+    self:desktop():insert(label:new("title", rect {0, 0, 12, 1}, "hello xmake!"):textattr_set("white"), {centerx = true})
+
+    -- add yes button
+    self:desktop():insert(button:new("yes", rect {0, 1, 7, 2}, "< Yes >"):textattr_set("white"), {centerx = true})
+
+    -- add no button
+    self:desktop():insert(button:new("no", rect {0, 2, 6, 3}, "< No >"):textattr_set("white"), {centerx = true})
+end
+
+-- on event
+function demo:event_on(e)
+    if application.event_on(self, e) then
+        return true
+    end
+    if e.type == event.ev_keyboard then
+        self:statusbar():info():text_set(e.key_name)
+        if e.key_name == "s" then
+            self:statusbar():show(not self:statusbar():state("visible"))
+        elseif e.key_name == "m" then
+            self:menubar():show(not self:menubar():state("visible"))
+        elseif e.key_name == "d" then
+            self:desktop():show(not self:desktop():state("visible"))
+        end
+    end
+end
+
+-- main entry
+demo:run()