Abstract: A locking system is disclosed for securing and locking sliding panels such as doors or windows of the type in which the opening and closing movement of a sliding panel occurs in a plane adjacent and generally perpendicular to a fixed surface which is substantially parallel to a side edge of the sliding panel. The system comprises first and second locking bars of predetermined fixed length for being positioned between one side edge of a sliding panel and one fixed surface opposite that side edge. First bracket means are mounted either upon the one side edge or upon the opposite fixed surface, and support one respective end of each of the first and second locking bars adjacent one another, and thereby maintain the ends against the side edge or the fixed surface. Second bracket means are mounted upon the other of the side edge or the opposite fixed surface, and support the other respective end of each of the locking bars in spaced relationship to one another.