Show popup notification from Chrome Extension

Chrome_Notification.js

var options = {
    type: 'basic',
    iconUrl: 'images/app_icon.png',
    title: chrome.i18n.getMessage("appName"),
    message: chrome.i18n.getMessage("notif_message"), //You haven't made entry to your diary. Want to finish now ?
    buttons: [
      {
        title: chrome.i18n.getMessage("add_now")
      }
    ]
  };

  var notifid = "1";

  chrome.notifications.create(notifid, options, function(id) {console.log("notification shown");});
  chrome.notifications.onButtonClicked.addListener(function(notificationId, buttonIndex) {
    if(notificationId === notifid) {
      if (buttonIndex === 0) {
        console.log("Add button clicked");
        chrome.notifications.clear(notificationId, function() {});
      } 
    }
  });