A handle for active frame events. Includes the member :GetTarget(), which returns the target frame of this event. If being passed to a .Dive handler, also includes :Halt() and :Catch(). :Halt() halts propogation of the event through the hierarchy and, after finishing the current frame's .Dive handlers, immediately begins processing .Bubble events. :Catch() works similarly but processes main events before continuing to .Bubble. Neither function may be called when the environment is in secure mode and either the current or target frame has a restricted secure mode.