a bit of hero window

help needed - make something to prevent changing surface stored in CHeroWindow::background. I do not overwrite it, but it changes dramatically with every call of CHeroWindow method!

And besides - is there anything to make my window displayed easily, without calling show() every frame when it should be displayed? any machanism?

CHeroWindow.h

@@ -0,0 +1,16 @@
+#pragma once
+#include "CPlayerInterface.h"
+
+class SDL_Surface;
+class CGHeroInstance;
+
+class CHeroWindow: public IShowable, public virtual CIntObject
+{
+	SDL_Surface * background;
+	const CGHeroInstance * curHero;
+public:
+	CHeroWindow(); //c-tor
+	~CHeroWindow(); //d-tor
+	void setHero(const CGHeroInstance * hero); //sets main displayed hero
+	virtual void show(SDL_Surface * to = NULL); //shows hero window
+};