gistfile1.js

  Template.layout.events({
    'click .terms-modal': function() {
      Session.set('showTermsModal', true);
    }
  });

  Template.layout.helpers({
    termsModalOpen: function() {
      return !!Session.get('showTermsModal');
    }
  });

  Template.termsModal.events({
    'click .close': function() {
      Session.set('showTermsModal', false);
    }
  });