Great, man, you made it into the holy heart of the European Central Bank!
The only thing you have to do now is:
Crack the 4-digit-code of the safe's door in maximum 10 attempts!
Set digits with the keypad on the door. Delete a whole row of your code by clicking "C". You can delete a certain digit by clicking "CE" and the number of its position.
If you think your code is correct, click the stethoscope to get the information how many digits are set correctly (right digit in right position) and how many digits are in a wrong position. Notice! Any digit can be found more than once.
Advanced safecrackers try a 5-digit- ("F"-) or a 6-digit-code ("P"-Button).
If you need the pressure of time, hit the clock, set your minutes with the keypad and hit the clock again to start the countdown.
Much luck - and brain!
For a new try: hit the door's wheel.