Described is a locking mechanism for a lock box comprising a plurality of buttons connected to either a sliding dawg or a dummy dawg. The sliding and dummy dawgs are supported by a retaining bar in a first position and can slide into a second position when its corresponding button is pressed. Each dawg comprises a hook that is adapted to engage with a lock bar. The sliding dawgs have hooks that are engaged with the lock bar until the corresponding button is pressed, while the dummy dawgs have hooks that are not engaged with the lock bar unless the corresponding button is pressed. The locking mechanism locks if a button corresponding to a dummy dawg has been pressed, and the locking mechanism can then be opened only by use of a key. The locking mechanism opens if the correct buttons are pressed, regardless of the sequence.