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This API is available on Firefox OS for internal applications only.

The onalerting event handler of the TelephonyCall interface is a reference to a function to be called to handle the Telephony API's alerting event.

The event handler is called with a CallEvent as its only parameter.


myCall.onalerting = function() { ... };


// Telephony object
var tel = navigator.mozTelephony;

// Place a call
tel.dial("123456789").then(function(call) {

  call.onalerting = function() {
    // respond to alerting


Specification Status Comment
Web Telephony Draft Draft.

Browser compatibility

For obvious reasons, support is primarily expected on mobile browsers.

Supported in Firefox OS 1.0.1.

See also

Document Tags and Contributors

 Contributors to this page: fscholz, chrisdavidmills, teoli, MHasan, kscarfone, Jeremie
 Last updated by: fscholz,