A method and an adjustable locking system for sliding windows and/or sliding doors are provided. The adjustable locking system includes a slide rail, a jammer bar, and a sliding spring-loaded pull pin lock. The slide rail mounts flush to the action portion of the sliding window or sliding door frame. The spring loaded locking pin is attached to the jammer bar which slides through the slide rail; engaging in a series of optional locking points allowing the window or door to be securely locked anywhere in between fully open to fully closed.