GtkNotebook

Hi, I have a problem with a GtkNotebook. When I use the append_page or insert_page function into the main program, it works. But when I use them into another function the new page does not show on the screen. It seems to create page into memory but does not show. I try to use the show function but it also does not work. What's wrong ? My code : $notebook = new GtkNotebook(); $notebook->append_page(new GtkLabel("title"), new GtkLabel("content")); --> it works function test(){ global $notebook; $notebook->append_page(new GtkLabel("title"), new GtkLabel("content")); } --> it does not work Thanks, Breizh.