The invention relates to a locking system for locking a lid of a portable electronic device, comprising at least a latch, a detent and a first return member. The latch has at least a first position of the latch and a second position of the latch, wherein the latch is connected to the lid in the first position of the latch, and the latch is disconnected from the lid in the second position of the latch. The detent has at least a first position of the detent and a second position of the detent, and the detent is adjusted to detain the latch in the second position of the latch. The first return member is adjusted to move the latch from the second position of the latch to the first position of the latch.