At the bottom of the window is a plastic tab. When the tab breaks, the expensive solution is to purchase a window as Isuzu does not sell just the tabs. Several members of the site have glued the tabs back in place using various strong glues or epoxies. Fixing the tabs is not the only solution you should look into.. there are the causes that contribute to your problem. Nice thing is that several member's here have taken time and photographs helping to describe their fixes.