get ready for Linux

source/gui/element.cpp

@@ -1,7 +1,7 @@
 /*
 *	Elements of GUI Gadgets
 *	Nana C++ Library(http://www.nanapro.org)
-*	Copyright(C) 2003-2014 Jinhao(cnjinhao@hotmail.com)
+*	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
 *
 *	Distributed under the Boost Software License, Version 1.0.
 *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -411,7 +411,7 @@ namespace nana
 						pixels -= 2;
 					}
 				}
-				break;
+				default:break;
 				}
 				return true;
 			}