diff --git a/include/nana/internationalization.hpp b/include/nana/internationalization.hpp
index 1b434169..4b3e3918 100644
--- a/include/nana/internationalization.hpp
+++ b/include/nana/internationalization.hpp
@@ -24,6 +24,9 @@ namespace nana
 	{
 		friend class i18n_eval;
 	public:
+		/// Sets a handler to handle a msgid which hasn't been translated.
+		static void set_missing(std::function<void(const std::string& msgid_utf8)> handler);
+
 		void load(const std::string& file);
 		void load_utf8(const std::string& file);
 
diff --git a/source/gui/filebox.cpp b/source/gui/filebox.cpp
index 07752e41..ec6c08a5 100644
--- a/source/gui/filebox.cpp
+++ b/source/gui/filebox.cpp
@@ -50,7 +50,7 @@ namespace nana
 			{
 				std::wstring type;
 				ires>>m.name>>type>>type;
-				m.directory = (type == L"Directory");
+				m.directory = (to_utf8(type) == internationalization()("NANA_FILEBOX_DIRECTORY"));
 				return ires;
 			}
 
@@ -65,6 +65,8 @@ namespace nana
 				_m_add(tm, item.modified_time.tm_min)<<':';
 				_m_add(tm, item.modified_time.tm_sec);
 
+				internationalization i18n;
+
 				ores<<item.name<<tm.str();
 				if(!item.directory)
 				{
@@ -72,12 +74,12 @@ namespace nana
 					if(pos != item.name.npos && (pos + 1 < item.name.size()))
 						ores<<item.name.substr(pos + 1);
 					else
-						ores<<L"File";
+						ores<<i18n("NANA_FILEBOX_FILE");
 
 					ores<<_m_trans(item.bytes);
 				}
 				else
-					ores<<L"Directory";
+					ores << i18n("NANA_FILEBOX_DIRECTORY");
 				return ores;
 			}
 
@@ -114,7 +116,8 @@ namespace nana
 
 					return s + ustr[uid];
 				}
-				ss<<bytes<<" Bytes";
+				internationalization i18n;
+				ss<<bytes<<" "<<i18n("NANA_FILEBOX_BYTES");
 				return ss.str();
 			}
 		};
@@ -138,6 +141,7 @@ namespace nana
 		filebox_implement(window owner, bool io_read, const std::string& title)
 			: form(owner, API::make_center(owner, 630, 440)), io_read_(io_read)
 		{
+			internationalization i18n;
 			path_.create(*this);
 			path_.splitstr("/");
 			path_.events().selected.connect_unignorable([this](const arg_categorize<int>&)
@@ -157,7 +161,7 @@ namespace nana
 
 			filter_.create(*this);
 			filter_.multi_lines(false);
-			filter_.tip_string("Filter");
+			filter_.tip_string(i18n("NANA_FILEBOX_FILTER"));
 
 			filter_.events().key_release.connect_unignorable([this](const arg_keyboard&)
 			{
@@ -165,23 +169,23 @@ namespace nana
 			});
 
 			btn_folder_.create(*this);
-			btn_folder_.caption("&New Folder");
+			btn_folder_.i18n(i18n_eval("NANA_FILEBOX_NEW_FOLDER_SHORTKEY"));
 
 			btn_folder_.events().click.connect_unignorable([this](const arg_click&)
 			{
 				form fm(this->handle(), API::make_center(*this, 300, 35));
-				fm.caption("Name the new folder");
+				fm.i18n(i18n_eval("NANA_FILEBOX_NEW_FOLDER_CAPTION"));
 
 				textbox folder(fm, nana::rectangle(5, 5, 160, 25));
 				folder.multi_lines(false);
 
 				button btn(fm, nana::rectangle(170, 5, 60, 25));
-				btn.caption("Create");
+				btn.i18n(i18n_eval("NANA_BUTTON_CREATE"));
 
 				btn.events().click.connect_unignorable(folder_creator(*this, fm, folder));
 
 				button btn_cancel(fm, nana::rectangle(235, 5, 60, 25));
-				btn_cancel.caption("Cancel");
+				btn_cancel.i18n(i18n_eval("NANA_BUTTON_CANCEL"));
 
 				btn_cancel.events().click.connect_unignorable([&fm](const arg_click&)
 				{
@@ -193,10 +197,10 @@ namespace nana
 			tree_.create(*this);
 
 			ls_file_.create(*this);
-			ls_file_.append_header("Name", 190);
-			ls_file_.append_header("Modified", 145);
-			ls_file_.append_header("Type", 80);
-			ls_file_.append_header("Size", 70);
+			ls_file_.append_header(i18n("NANA_FILEBOX_HEADER_NAME"), 190);
+			ls_file_.append_header(i18n("NANA_FILEBOX_HEADER_MODIFIED"), 145);
+			ls_file_.append_header(i18n("NANA_FILEBOX_HEADER_TYPE"), 80);
+			ls_file_.append_header(i18n("NANA_FILEBOX_HEADER_SIZE"), 70);
 
 			auto fn_sel_file = [this](const arg_mouse& arg){
 				_m_sel_file(arg);
@@ -274,7 +278,7 @@ namespace nana
 				});
 
 			lb_file_.create(*this);
-			lb_file_.caption("File:");
+			lb_file_.i18n(i18n_eval("NANA_FILEBOX_FILE_COLON"));
 			
 			tb_file_.create(*this);
 			tb_file_.multi_lines(false);
@@ -290,14 +294,15 @@ namespace nana
 			cb_types_.events().selected.connect_unignorable([this](const arg_combox&){ _m_list_fs(); });
 
 			btn_ok_.create(*this);
-			btn_ok_.caption("&OK");
+			btn_ok_.i18n(i18n_eval("NANA_BUTTON_OK_SHORTKEY"));
+
 
 			btn_ok_.events().click.connect_unignorable([this](const arg_click&)
 			{
 				_m_ok();
 			});
 			btn_cancel_.create(*this);
-			btn_cancel_.caption("&Cancel");
+			btn_cancel_.i18n(i18n_eval("NANA_BUTTON_CANCEL_SHORTKEY"));
 
 			btn_cancel_.events().click.connect_unignorable([this](const arg_click&)
 			{
@@ -309,7 +314,7 @@ namespace nana
 			_m_init_tree();
 
 			if(0 == title.size())
-				caption(io_read ? "Open" : "Save As");
+				this->i18n(i18n_eval(io_read ? "NANA_FILEBOX_OPEN" : "NANA_FILEBOX_SAVE_AS"));
 			else
 				caption(title);
 		}
@@ -640,11 +645,12 @@ namespace nana
 			{
 				auto path = tx_path_.caption();
 
-				msgbox mb(fm_, "Create Folder");
+				internationalization i18n;
+				msgbox mb(fm_, i18n("NANA_FILEBOX_NEW_FOLDER"));
 				mb.icon(msgbox::icon_warning);
 				if(0 == path.size() || path[0] == '.' || path[0] == '/')
 				{
-					mb<<L"Please input a valid name for the new folder.";
+					mb << i18n("NANA_FILEBOX_ERROR_INVALID_FOLDER_NAME");
 					mb();
 					return;
 				}
@@ -657,14 +663,14 @@ namespace nana
 
 				if(fst.type() != file_type::not_found && fst.type() != file_type::none)
 				{
-					mb<<L"The folder is existing, please rename it.";
+					mb<<i18n("NANA_FILEBOX_ERROR_RENAME_FOLDER_BECAUSE_OF_EXISTING");
 					mb();
 					return;
 				}
 
 				if(false == fs::create_directory(fspath))
 				{
-					mb<<L"Failed to create the folder, please rename it.";
+					mb<<i18n("NANA_FILEBOX_ERROR_RENAME_FOLDER_BECAUSE_OF_FAILED_CREATION");
 					mb();
 					return;
 				}			
@@ -741,11 +747,12 @@ namespace nana
 				auto file = tb_file_.caption();
 				if(file.size())
 				{
+					internationalization i18n;
 					if(file[0] == '.')
 					{
 						msgbox mb(*this, caption());
 						mb.icon(msgbox::icon_warning);
-						mb<<file<<std::endl<<"The filename is invalid.";
+						mb<<file<<std::endl<<i18n("NANA_FILEBOX_ERROR_INVALID_FILENAME");
 						mb();
 						return;
 					}
@@ -780,7 +787,7 @@ namespace nana
 						{
 							msgbox mb(*this, caption());
 							mb.icon(msgbox::icon_information);
-							mb<<"The file \""<<tar<<"\"\n is not existing. Please check and retry.";
+							mb << i18n("NANA_FILEBOX_ERROR_NOT_EXISTING_AND_RETRY", tar);
 							mb();
 
 							return;
@@ -792,7 +799,7 @@ namespace nana
 						{
 							msgbox mb(*this, caption(), msgbox::yes_no);
 							mb.icon(msgbox::icon_question);
-							mb<<"The input file is existing, do you want to overwrite it?";
+							mb<<i18n("NANA_FILEBOX_ERROR_QUERY_REWRITE_BECAUSE_OF_EXISTING");
 							if(msgbox::pick_no == mb())
 								return;
 						}
diff --git a/source/gui/msgbox.cpp b/source/gui/msgbox.cpp
index 4bafd225..6b3b9510 100644
--- a/source/gui/msgbox.cpp
+++ b/source/gui/msgbox.cpp
@@ -61,14 +61,14 @@ namespace nana
 				{
 					_m_click(arg);
 				});
-				yes_.i18n(i18n_eval("OK"));
+				yes_.i18n(i18n_eval("NANA_BUTTON_OK"));
 				width_pixel += 77;
 
 				if(msgbox::yes_no == btn || msgbox::yes_no_cancel == btn)
 				{
-					yes_.i18n(i18n_eval("Yes"));
+					yes_.i18n(i18n_eval("NANA_BUTTON_YES"));
 					no_.create(*this);
-					no_.i18n(i18n_eval("No"));
+					no_.i18n(i18n_eval("NANA_BUTTON_NO"));
 					no_.events().click.connect_unignorable([this](const arg_click& arg)
 					{
 						_m_click(arg);
@@ -79,7 +79,7 @@ namespace nana
 					if(msgbox::yes_no_cancel == btn)
 					{
 						cancel_.create(*this);
-						cancel_.i18n(i18n_eval("Cancel"));
+						cancel_.i18n(i18n_eval("NANA_BUTTON_CANCEL"));
 						cancel_.events().click.connect_unignorable([this](const arg_click& arg)
 						{
 							_m_click(arg);
@@ -493,7 +493,7 @@ namespace nana
 			auto desc_extent = desc_.measure(470);
 
 			btn_ok_.create(*this);
-			btn_ok_.i18n(i18n_eval("OK"));
+			btn_ok_.i18n(i18n_eval("NANA_BUTTON_OK"));
 			btn_ok_.events().click.connect_unignorable([this]{
 
 				if (verifier_ && !verifier_(handle()))
@@ -504,7 +504,7 @@ namespace nana
 			});
 
 			btn_cancel_.create(*this);
-			btn_cancel_.i18n(i18n_eval("Cancel"));
+			btn_cancel_.i18n(i18n_eval("NANA_BUTTON_CANCEL"));
 			btn_cancel_.events().click.connect_unignorable([this]{
 				close();
 			});
@@ -1141,7 +1141,7 @@ namespace nana
 		impl->path_edit.multi_lines(false);
 
 		impl->browse.create(impl->dock);
-		impl->browse.i18n(i18n_eval("Browse"));
+		impl->browse.i18n(i18n_eval("NANA_BUTTON_BROWSE"));
 		impl->browse.events().click.connect_unignorable([wd, impl](const arg_click&)
 		{
 			impl->fbox.owner(wd);
diff --git a/source/internationalization.cpp b/source/internationalization.cpp
index 10098ab1..375b7434 100644
--- a/source/internationalization.cpp
+++ b/source/internationalization.cpp
@@ -151,7 +151,44 @@ namespace nana
 
 		struct data
 		{
+			std::function<void(const std::string&)> on_missing;
 			std::unordered_map<std::string, std::string> table;
+
+			data()
+			{
+				//initializes nana's translation
+				table["NANA_BUTTON_OK"] = "OK";
+				table["NANA_BUTTON_OK_SHORTKEY"] = "&OK";
+				table["NANA_BUTTON_YES"] = "Yes";
+				table["NANA_BUTTON_NO"] = "No";
+				table["NANA_BUTTON_BROWSE"] = "Browse";
+				table["NANA_BUTTON_CANCEL"] = "Cancel";
+				table["NANA_BUTTON_CANCEL_SHORTKEY"] = "&Cancel";
+				table["NANA_BUTTON_CREATE"] = "Create";
+		
+				table["NANA_FILEBOX_BYTES"] = "Bytes";
+				table["NANA_FILEBOX_FILESYSTEM"] = "FILESYSTEM";
+				table["NANA_FILEBOX_FILTER"] = "Filter";
+				table["NANA_FILEBOX_NEW_FOLDER"] = "New Folder";
+				table["NANA_FILEBOX_NEW_FOLDER_SHORTKEY"] = "&New Folder";
+				table["NANA_FILEBOX_HEADER_NAME"] = "Name";
+				table["NANA_FILEBOX_HEADER_MODIFIED"] = "Modified";
+				table["NANA_FILEBOX_HEADER_TYPE"] = "Type";
+				table["NANA_FILEBOX_HEADER_SIZE"] = "Size";
+				table["NANA_FILEBOX_NEW_FOLDER_CAPTION"] = "Name the new folder";
+
+				table["NANA_FILEBOX_SAVE_AS"] = "Save As";
+				table["NANA_FILEBOX_OPEN"] = "Open";
+				table["NANA_FILEBOX_DIRECTORY"] = "Directory";
+				table["NANA_FILEBOX_FILE"] = "File";
+				table["NANA_FILEBOX_FILE_COLON"] = "File:";
+				table["NANA_FILEBOX_ERROR_INVALID_FOLDER_NAME"] = "Please input a valid name for the new folder.";
+				table["NANA_FILEBOX_ERROR_RENAME_FOLDER_BECAUSE_OF_EXISTING"] = "The folder is existing, please rename it.";
+				table["NANA_FILEBOX_ERROR_RENAME_FOLDER_BECAUSE_OF_FAILED_CREATION"] = "Failed to create the folder, please rename it.";
+				table["NANA_FILEBOX_ERROR_INVALID_FILENAME"] = "The filename is invalid.";
+				table["NANA_FILEBOX_ERROR_NOT_EXISTING_AND_RETRY"] = "The file \"%arg0\"\n is not existing. Please check and retry.";
+				table["NANA_FILEBOX_ERROR_QUERY_REWRITE_BECAUSE_OF_EXISTING"] = "The input file is existing, do you want to overwrite it?";
+			}
 		};
 
 		static std::shared_ptr<data>& get_data_ptr()
@@ -293,6 +330,10 @@ namespace nana
 		}
 	}//end namespace internationalization_parts
 
+	void internationalization::set_missing(std::function<void(const std::string& msgid_utf8)> handler)
+	{
+		internationalization_parts::get_data_ptr()->on_missing = std::move(handler);
+	}
 
 	void internationalization::load(const std::string& file)
 	{
@@ -324,6 +365,9 @@ namespace nana
 		if (i != impl->table.end())
 			return i->second;
 
+		if (impl->on_missing)
+			impl->on_missing(msgid);
+
 		return std::move(msgid);
 	}