diff -urN cui36/cui.c cui37/cui.c
--- cui36/cui.c	Fri Jan 31 01:10:00 2014
+++ cui37/cui.c	Fri Jan 31 01:30:00 2014
@@ -188,6 +188,7 @@
 {
 	obj->flags |= CUI_FLG_HIDE;
 	cui_clear(obj);
+	if(obj == cui_focus_get()) cui_focus_set(NULL);
 }
 
 void
@@ -218,6 +219,13 @@
 	return cui_rect_and(r, t, r); /* r and t --> r */
 }
 
+int
+cui_is_visible_rect(cui obj)
+{
+	struct cui_rect tmp;
+	return cui_visible_rect(obj, &tmp);
+}
+
 void
 cui_xywh_set(cui obj, int x, int y, int w, int h)
 {
@@ -228,6 +236,7 @@
 	obj->w = w;
 	obj->h = h;
 	if(visi) cui_show(obj);
+	if(obj == cui_focus_get() && !cui_is_visible_rect(obj)) cui_focus_set(NULL);
 }
 
 void
diff -urN cui36/cui.h cui37/cui.h
--- cui36/cui.h	Fri Jan 31 01:10:00 2014
+++ cui37/cui.h	Fri Jan 31 01:30:00 2014
@@ -54,6 +54,7 @@
 void cui_show(cui obj);
 int cui_is_visible(cui obj);
 int cui_visible_rect(cui obj, cui_rect r);
+int cui_is_visible_rect(cui obj);
 void cui_xywh_set(cui obj, int x, int y, int w, int h);
 void cui_x_set(cui obj, int x);
 void cui_w_set(cui obj, int w);
diff -urN cui36/focus.c cui37/focus.c
--- cui36/focus.c	Fri Jan 31 01:10:00 2014
+++ cui37/focus.c	Fri Jan 31 01:30:00 2014
@@ -40,6 +40,7 @@
 	if(obj == focus) return old;
 	if(!(obj->flags & CUI_FLG_CAN_FOCUS)) return old;
 	if(!cui_is_visible(obj)) return old;
+	if(!cui_is_visible_rect(obj)) return old;
 	switch(key){
 	case CUI_KEY_UP:
 	case CUI_KEY_DOWN: