put a button on a menuitem, when click mouse button on the menuitem, it seems that button does not receive it

["cheng bo" <chengbobo831005 gmail com>]

code snipper:

GtkMenu * menu = gtk_menu_new( ) ;
GtkMenuItem * item = gtk_menu_item_new( );
GtkWideget  * b = gtk_button_new_with_label("asdada");
gtk_containter_add((GtkContainer*)item, b ) ;

gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);

g_signal_connect(G_OBJECT(b), "entry", G_CALLBACK(cb_function), NULL);

after that, catch the button_release_event to make sure that menu will
not disapper ..

but it seems that button b does not emit the entry signal,cb_function
is not called ,somebody  give me some guides?
                                                        thanks