to fredck : in fck 2.6 i need to get into RegisteredEvents

well i try to get into RegisteredEvents[ eventName ] but i dont know how,
in fck 2.3.2 i use the function:

FCKEvents.prototype.FireEvent = function( eventName, params )
{
var oCalls = this.RegisteredEvents[ eventName ] ;
}

and it works good

and now i try to use the same on fck 2.6
and it not work

can you please tall me why ?
and if there is alternative way to get into RegisteredEvents[ eventName ] ;
thanks