var validationSet = {
  'email': {
    'regexp': /^.+?@.+?\..+$/,
    'error': 'This email address is invalid. ' +
        'It should be of the form someone@example.com.'
  },
  'phone': {
    'regexp': /^[- ()0-9]+$/,
    'error': 'A phone number must be digits only.'
  },
  'first_name': {
    'regexp': /^[a-z]+$/gi,
    'error': 'First name is required and must be letters only. '
  },
  'last_name': {
    'regexp': /^[a-z]+$/gi,
    'error': 'Last name is required and must be letters only. '
  }
};