Create a new window in the given channel.
Return : ObjGtkWidget : the new gtk window or nil if an error occurs
typeof gtkWin = ObjGtkWidget;; fun cbWinClose (obj, user_param)= _gtkWidgetDestroy obj; _fooS "window closed !"; _gtkMainQuit; 0;; fun main ()= _showconsole; set gtkWin = _gtkWindowNew _channel nil "Test" [50 50] [400 350]; _gtkWidgetShow gtkWin; _gtkWindowCBdestroyed gtkWin @cbWinClose 0; _gtkMain; 0;;