This API is available on Firefox OS for internal applications only.
Summary
The oncfstatechange property specifies an event listener to receive cfstatechange events. These events occur when the call forwarding state changes.
Note: MozMobileConnection inherits from the EventTarget interface, so it's also possible to listen for events by using the addEventListener() method.
Syntax
navigator.mozMobileConnection.oncfstatechange = funcRef;
Where funcRef is a function to be called when the cfstatechange event occurs.
Specification
Not part of any specification.