I made it in my game
Get the Girl!
I used an array XY, where X is the "World" and Y is the Level. And I set 1 to each array value when the level is unlocked. So... My array would be something like:
 = 1; (first level should be set unlocked by default on layout start)
 = 0; (means unlocked)
 = 1; (meansl locked);
... and so on...
then I have a loop to this array that checks if it?s locked or unlocked then allows to click on the respective button and changes it?s animation frame.
If you don?t understand let me know, then I try to make a simple capx to explain.