1.  Field of the Invention
The present invention relates to a lock for securing an article on display and, more particularly, to such a lock which is easy to be operated and convenient to be well kept. 
2.  Description of Related Art
There is often a need to secure an article on display, especially on public display.  This is usually accomplished by a lock that has a wire cable looped through something immovable. 
As shown in FIG.  5, a lock for this purpose generally includes a main body (50) having a plurality of dials (51) and a socket (52) for detachably receiving a separate hitching part (60).  After or before a front hook of the hitching part (60) passes through a port in an article, the dials (51) are required to be turned into the preset combination to allow the rear disk-like end of the part (60) to be placed into the socket (52) and fixedly attached to the main body (50). 
The lock is opened by turning the dials (51) into the present combination again before moving a slider (53) of the main body (50).  It is at this time that the hitching part (60) can be detached from the main body (50). 
In this conventional lock, it is clear that the dials (51) must be turned either for the attachment of the hitching part (60) to or the detachment of the hitching part (60) from the main body (50), which is a difficult operation for a user. 
Additionally, the conventional lock is not convenient to be well kept because the separate hitching part (60) is often lost and the remaining main body (50) becomes useless. 
Therefore, it is an objective of the invention to provide a lock for securing an article on display to mitigate and/or obviate the aforementioned problems.