Turns off mouse event capture mode that had been engaged earlier by the setCapture( ) method. In the IE event model, mouse event capture is designed for temporary use, such as processing mouse events while a custom context menu (implemented as a positioned div element) is activated. IE event capture is also released automatically by several user actions: giving focus to another window, frame, or the browser's Address box; scrolling a window; displaying a system dialog box; or displaying the true context menu.