readonly attribute DOMString number;
// "dialing", "ringingalerting", "busy", "connecting", "connected", "disconnecting", "disconnected", "incoming"
// Add new states: "holding", "held", "resuming"
readonly attribute DOMString state;
//make a "connected" call into "held"
void holdCallhold();
//make a "held" call back to "connected"
void resumeCallresume();
attribute nsIDOMEventListener onstatechange;
attribute nsIDOMEventListener ondialing;
attribute nsIDOMEventListener onringingonalerting;
attribute nsIDOMEventListener onbusy;
attribute nsIDOMEventListener onconnecting;