Hi ,i am trying to add a smart button to my view which calculates the sum of total aides donated to a person this is  a part of the codeperson.py

def _aide_total(self, cr, uid, ids, field_name, arg, context=None):

res = {}

for aide in self.person_aide_ids.browse(cr, uid, ids, context=context):

total = 0.0

for line in aide.person_aide_valeur:

total += line.person_aide_valeur

res[aide.id] = total

return res

_name='person'

columns={

                 'person_aide_ids':fields.one2many('person.aide', 'person_id', 'المساعدات', required=False),

                 'total_person_aides': fields.function(_aide_total,string="القيمة الجملية للمساعدات", type='float'),

}

aide.py

        'person_aide_valeur':fields.float('قيمة المساعدة'),

person.xml:(only the button code)

<button type="action" class="oe_stat_button" icon="fa-pencil-square-o" name="المساعدات">

<field name="total_person_aides" string="المساعدات" widget="statinfo"/>

</button>

The button did not work
Can any one help me  
and thinks