diff -urN cui30/cui.c cui31/cui.c
--- cui30/cui.c	Fri Jan 31 00:10:00 2014
+++ cui31/cui.c	Fri Jan 31 00:30:00 2014
@@ -11,8 +11,39 @@
 #include <string.h>
 #include <unistd.h>
 
-cui cui_focus = NULL;
-int cui_running = FALSE;
+typedef struct cui_main_stack *cui_main_stack;
+
+struct cui_main_stack{
+	cui focus;
+	int running;
+	cui_main_stack prev;
+};
+
+static cui_main_stack main_stack = NULL;
+
+cui
+cui_focus_get(void)
+{
+	return main_stack ? main_stack->focus : NULL;
+}
+
+void
+cui_focus_set(cui obj)
+{
+	if(main_stack) main_stack->focus = obj;
+}
+
+int
+cui_running_get(void)
+{
+	return main_stack ? main_stack->running : FALSE;
+}
+
+void
+cui_running_set(int v)
+{
+	if(main_stack) main_stack->running = v;
+}
 
 cui
 cui_alloc(int size)
@@ -135,7 +166,7 @@
 int
 cui_focus_move_val(cui obj, int key)
 {
-	if(cui_focus) return cui_glen(obj, cui_focus);
+	if(cui_focus_get()) return cui_glen(obj, cui_focus_get());
 
 	switch(key){
 	case CUI_KEY_UP:
@@ -154,12 +185,13 @@
 cui_focus_move_judge(cui obj, int key, cui old, int *val)
 {
 	int v, jg = FALSE;
+	cui focus = cui_focus_get();
 
 	if(obj == NULL) return old;
 	old = cui_focus_move_judge(obj->next, key, old, val);
 	old = cui_focus_move_judge(obj->children, key, old, val);
 
-	if(obj == cui_focus) return old;
+	if(obj == focus) return old;
 	if(!(obj->flags & CUI_FLG_CAN_FOCUS)) return old;
 	if(!cui_is_visible(obj)) return old;
 	switch(key){
@@ -173,19 +205,19 @@
 	}
 
 	v = cui_focus_move_val(obj, key);
-	if(cui_focus){
+	if(focus){
 		switch(key){
 		case CUI_KEY_UP:
-			jg = cui_gy(obj) <= cui_gy(cui_focus);
+			jg = cui_gy(obj) <= cui_gy(focus);
 			break;
 		case CUI_KEY_DOWN:
-			jg = cui_gy(obj) + obj->h >= cui_gy(cui_focus) + cui_focus->h;
+			jg = cui_gy(obj) + obj->h >= cui_gy(focus) + focus->h;
 			break;
 		case CUI_KEY_LEFT:
-			jg = cui_gx(obj) <= cui_gx(cui_focus);
+			jg = cui_gx(obj) <= cui_gx(focus);
 			break;
 		case CUI_KEY_RIGHT:
-			jg = cui_gx(obj) + obj->w >= cui_gx(cui_focus) + cui_focus->w;
+			jg = cui_gx(obj) + obj->w >= cui_gx(focus) + focus->w;
 			break;
 		}
 		if(old) jg = jg && v < *val;
@@ -214,7 +246,7 @@
 	
 	if(obj == NULL) return;
 	if(!cui_is_visible(obj)) return;
-	val = (obj == cui_focus) ? CUI_DRAW_FOCUS : CUI_DRAW_NORMAL;
+	val = (obj == cui_focus_get()) ? CUI_DRAW_FOCUS : CUI_DRAW_NORMAL;
 	cui_handler_call(obj, obj->handler_list, CUI_EVT_DRAW, val);
 	cui_draw_chain(obj->children);
 }
@@ -289,36 +321,45 @@
 void
 cui_quit(void)
 {
-	cui_running = FALSE;
+	cui_running_set(FALSE);
 }
 
 void
-cui_main(cui top_obj)
+cui_main(cui top_obj, cui init_focus)
 {
+	struct cui_main_stack stk;
+	cui_main_stack sp = (cui_main_stack)&stk;
+
 	int key, val;
-	cui obj, bak;
+	cui focus, obj;
+
+	sp->focus = init_focus;
+	sp->running = TRUE;
+	sp->prev = main_stack;
+	main_stack = sp;
 
 	cui_esc_enter();
 	cui_key_enter();
 
-	cui_running = TRUE;	
 	cui_clear(top_obj);
 	cui_draw(top_obj);
-	while(cui_running){
+	while(cui_running_get()){
 		if((key = cui_key_get2()) == 0) continue;
-		if(cui_focus){
-			if(cui_handler_call(cui_focus, cui_focus->handler_list, CUI_EVT_KEY, key)) continue;
+		focus = cui_focus_get();
+		if(focus){
+			if(cui_handler_call(focus, focus->handler_list, CUI_EVT_KEY, key)) continue;
 		}
 		obj = cui_focus_move_judge(top_obj, key, NULL, &val);
 		if(obj){
-			bak = cui_focus;
-			cui_focus = obj;
-			cui_draw(bak);
+			cui_focus_set(obj);
+			cui_draw(focus);
 			cui_draw(obj);
 		}
 	}
 	cui_key_exit();
 	cui_esc_exit();
+
+	main_stack = sp->prev;
 }
 
 void
diff -urN cui30/cui.h cui31/cui.h
--- cui30/cui.h	Fri Jan 31 00:10:00 2014
+++ cui31/cui.h	Fri Jan 31 00:30:00 2014
@@ -53,8 +53,13 @@
 void cui_x_set(cui obj, int x);
 void cui_w_set(cui obj, int w);
 
+cui cui_focus_get(void);
+void cui_focus_set(cui obj);
+int cui_running_get(void);
+void cui_running_set(int v);
+
 void cui_quit(void);
-void cui_main(cui top_obj);
+void cui_main(cui top_obj, cui init_focus);
 void cui_free(cui obj);
 
 #endif
diff -urN cui30/cui_test.c cui31/cui_test.c
--- cui30/cui_test.c	Fri Jan 31 00:20:00 2014
+++ cui31/cui_test.c	Fri Jan 31 00:30:00 2014
@@ -7,8 +7,6 @@
 #include "button.h"
 #include "dialog.h"
 
-extern cui cui_focus;
-
 int
 joke_hdr(cui obj, int evt, int val, void *prm)
 {
@@ -20,11 +18,11 @@
 		cui_button_str_set(b1, "sorry");
 		cui_x_set(b1, lb->w + 1);
 		cui_hide(b2);
-		cui_focus = b1;
+		cui_focus_set(b1);
 		cui_w_set(lb, b1->x + b1->w);		
 	}else{
 		cui_hide(lb);	
-		cui_focus = NULL;
+		cui_focus_set(NULL);
 		cui_draw(lb->parent);
 	}
 	return TRUE;
@@ -39,7 +37,7 @@
 	cui_w_set(lb, b2->x + b2->w);
 	cui_bind(b1, CUI_EVT_BUTTON, joke_hdr, lb);
 	cui_bind(b2, CUI_EVT_BUTTON, joke_hdr, lb);
-	cui_focus = b1;
+	cui_focus_set(b1);
 	cui_draw(lb);
 	return lb;
 }
@@ -78,7 +76,7 @@
 	cui_bind(btn, CUI_EVT_BUTTON, my_hdr2, p);
 	cui_bind(p->btn1, CUI_EVT_BUTTON, my_hdr, p);
 
-	cui_main(base);
+	cui_main(base, NULL);
 	printf("result %s\n", p->btn_result);
 	cui_free(base);
 	return 0;