In an ActionScript 3 (AS3) Flash Player movie (SWF), mouseMove events assigned to display objects stop firing when the mouse moves off the display object to which it was assigned. If you drag a display object using the mouseMove event, the mouseMove event may stop functioning if you move the mouse too fast, preventing the object from being dragged until the mouse is moved back over the object.
In ActionScript 3, mouseMove events are no longer global. MouseMove is now specific to the display object dispatching the event and only fires when the mouse moves from one location over the object to another location also over the object. If the mouse moves to a new location that is not over the display object dispatching the event, the event is not fired. When you attempt to use the mouseMove event to handle the dragging of a display object, it is possible the mouse may be moved fast enough to where its next position is off the object and thereby causes the drag (mouseMove event) to stop.
Fora global mouseMove event, assign listeners to the stage object. The stage object will always receive mouseMove events despite what other displayobjects the mouse is over (as long as the mouse moves within the Flash Player window). This way ifan object is being dragged,and the mouse moves off the object, the mouseMove event will still fire and the object will continue to follow the mouse.
Following is example code with assigned listeners: