Hi thank you for your answers !
I began with the method of fldr and I have some problems. (I certainly forgot a part).
Here is what I've done :
My Level Select Event Sheet: To launch every level, I have a specific button, the manipulation is then different. Here is how I made (for the event 32, i made an error, it's Play2 -> set locked to false) :
[attachment=2:u69l59fp][/attachment:u69l59fp]
I used for each "playbutton" sprite two instance variables. The boolean variable "unlocked" and the number variable "cur_lvl". (I put "false" for the first playbutton because the level is unlocked at the beginning). I add too on my first level two global variable (cur_level = 0 and cur_unlocked = 0 )
On the splash screen, I made as you :
[attachment=1:u69l59fp][/attachment:u69l59fp]
And on the level, I made this :
[attachment=0:u69l59fp][/attachment:u69l59fp]
When my guy is overlapping the finish flag, go to layout "missions" (level select), and put the boolean variable of playbutton2 (level 2) to false.
Where is the problem because it doesn't work. Thanks for your help