javascript arising eventuality object

i have an activex vigilant i hallowed an html page. i following activex vigilant emanate another object, nonetheless i need register an eventuality new vigilant created. vigilant awaiting an eventuality listener certain type.

i bucket same dll c# work fine. formula looks c#.

upload = obj.constructuploadobj(uploadconfig);
upload.statechanged += new uploadactionevents_statechangedeventhandler(upload_statechanged);

in javascript i have identical formula however i can't eventuality purebred object.

uploadaction = obj.constructuploadobj(uploadconfig);
uploadaction.statechanged = upload_statechanged;

function upload_statechanged(sender){
    writeline("uploadstate altered " + sender.getstate());
}

i have enumerated properties uploadaction vigilant javascript pledge indeed created. i try register eventuality uploadaction throws an blunder observant "object doesn't support ability method."

to me seems the awaiting strongly typed event. there anyway register eventuality identical c# javascript?

thanks advance.