titanium nfc basic

Im trying to alert something when my app is open and a mifare 1k card is sweep at the back of my note 1.

So this is my code:

var nfc = require('ti.nfc'); var nfcAdapter = null;

nfcAdapter = nfc.createNfcAdapter({ onNdefDiscovered: handleDiscovery, onTagDiscovered: handleDiscovery, onTechDiscovered: handleDiscovery });

if(!nfcAdapter.isEnabled()) { alert('Not nfc enabled'); return; }

function handleDiscovery(data) { alert('hey'); }

$.index.open();

Nothing happens everytime I sweep a card to my phone. Can someone help me?