how to create a button that you could light it with "up-down-left-right"key ?

[=?big5?b?tsC8eSBLYXNvbiBIdWFuZw==?= <kasonhuang kinposh com cn>]

hi,friends:
	I know how to create a button that you could light it  with mouse pointer.
you can :
	button_lower=gtk_button_new_with_label("Lower Case");
	gtk_table_attach_defaults(GTK_TABLE(table1),button_lower,0,1,1,2);
	current=gtk_widget_get_default_style();
	new_lower=gtk_style_copy(current);
	new_lower->bg[GTK_STATE_ACTIVE] = green;
	new_lower->bg[GTK_STATE_PRELIGHT] = cyan;
	gtk_widget_set_style(button_lower,new_lower);
	gtk_signal_connect(GTK_OBJECT(button_lower),"clicked",GTK_SIGNAL_FUNC(ShowNewWindow),NULL);
	gtk_widget_show(button_lower);
but "new_lower->bg[GTK_STATE_PRELIGHT] = cyan;" that working only when you mouse pointer on the button.i want to know
how to create a button that you could light it  with up-down-left-right key.should i use gtk_window_set_focus() to the button?
anyone knows it?


Thanks a lot!
kasonhuang kinposh com cn
                                                                               kason