Audible alert of incoming messages in webchat

Hi

I am currently using webchat(4.0.0) plug in my openfire server(3.6.3). when a new messsage arrives i am trying to Prouduce a ‘beep’ or ‘ding’ sound.

There is even an existing reference to a sound-related JavaScript function in webchat/chatmain.jsp, starting on line 364:

if (hasSounds != null && document.getElementById(“soundsEnabled”).checked) {
// play incoming sound, if enabled
document.getElementById(“sounds”).innerHTML=
"";
}

when i tryed to start a chat i get an exception “Could not load sound settings for workgroup demo@workgroup”.

Is there any setting is requied?