diff --git a/programs/cmm/lib/list_box.h b/programs/cmm/lib/list_box.h
index 6fde8e299b..d28524cdad 100644
--- a/programs/cmm/lib/list_box.h
+++ b/programs/cmm/lib/list_box.h
@@ -6,6 +6,7 @@ struct llist
 	int count, visible, first, current;
 	int current_temp;
 	void ClearList();
+	int ProcessKey(dword key);
 	int KeyDown();
 	int KeyUp();
 	int KeyHome();
@@ -49,6 +50,18 @@ int llist::MouseScroll(dword scroll_state)
 	return 0;
 }
 
+int llist::ProcessKey(dword key)
+{
+	switch(key)
+	{
+		case 177: return KeyDown();
+		case 178: return KeyUp();
+		case 180: return KeyHome();
+		case 181: return KeyEnd();
+	}
+	return 0;
+}
+
 int llist::KeyDown()
 {
 	if (current-first+1<visible)