iphone call status from iphone app

Hi,


I am currently working on an iphone app where i have to make a call from my iphone app, which i am able to do. But i want to know the status of the call i.e. whether the call is active, or diconnected and so on...

I found some code for this as below using CTCallCenter class of Core Telephony framework. The code is below...While implementing this i am getting some error. I am not understanding where exactly to use this. Can anyone help me out on this


CTCallCenter *callCenter = [[CTCallCenter alloc] init];

callCenter.callEventHandler=^(CTCall* call)
{

if (call.callState == CTCallStateDisconnected)
{

NSLog(@"Call has been disconnected");

}

else if (call.callState == CTCallStateConnected)
{

NSLog(@"Call has just been connected");

}

else if(call.callState == CTCallStateConnected)
{

NSLog(@"Call is incoming");

}

else
{

NSLog(@"None of the conditions");

}

};




Thanks in advance