menu scenes

how can I make the menu choice of scenes with the blocked levels are supported up to a not complete them? and if one falls out when the levels are supported is available completed?

Use a game number attribute to track the levels completed and then when the user clicks on a level, see if that attribute is high enough to start the level (I.e. If level >= 2, switch scene to level 2). Can also use this method with actor effects to gray out levels that are too high.

you tell me how to do that and behaviors used to create a scene menu
sorry but I do not know much about programming