IPhone : Show a view to receive call on pjsip incoming call iphone

I have got a problem while receiving incoming call.

I can able to receive incoming call and it automatically answers the pjsip VoIP call .

and I need a module when user can manually pic the call on button click .

This is where i am receiving incoming calls

static void on_incoming_call(pjsua_acc_id acc_id, pjsua_call_id call_id,
                         pjsip_rx_data *rdata){

pjsua_call_info ci;

PJ_UNUSED_ARG(acc_id);
PJ_UNUSED_ARG(rdata);

pjsua_call_get_info(call_id, &ci);

PJ_LOG(3,(THIS_FILE, "Incoming call from %.*s!!",
          (int)ci.remote_info.slen,
          ci.remote_info.ptr));
[[NSNotificationCenter defaultCenter] postNotificationName:@"appDidBecomeActive" object:nil];




/* Automatically answer incoming calls with 200/OK */
pjsua_call_answer(call_id, 200, NULL, NULL); }

What should i do that i can show an incoming call view there ( a button to pick up call and a button to hang up call ) .

Thanks in advance and please help me .