'Add a year of birth field to a form description.
Arguments:
form_desc: A form description
Keyword Arguments:
required (bool): Whether this field is required; defaults to True'

def _add_year_of_birth_field(self, form_desc, required=True):

    yob_label = _(u'Year    of    birth')
    options = [(unicode(year), unicode(year)) for year in UserProfile.VALID_YEARS]
    form_desc.add_field('year_of_birth', label=yob_label, field_type='select', options=options, include_default_option=True, required=required)
