columns={expr_date':fields.selection('Expire Date'),}

def product_id_change(self, cr, uid, ids, pricelist, product, qty=0, uom=False, qty_uos=0, uos=False, name='', partner_id=False, lang=False, update_tax=True, date_order=False, packaging=False, fiscal_position=False, flag=False, context=None):

    lang = lang or context.get('lang', False)
    if not  partner_id:
        raise osv.except_osv(_('No Customer Defined!'), _('Before choosing a product,\n select a customer in the sales form.'))
    warning = {}
    product_uom_obj = self.pool.get('product.uom')
    partner_obj = self.pool.get('res.partner')
    product_obj = self.pool.get('product.product')


    context = {'lang': lang, 'partner_id': partner_id}
    if partner_id:
        lang = partner_obj.browse(cr, uid, partner_id).lang
    context_partner = {'lang': lang, 'partner_id': partner_id}

    if not product:
        return {'value': {'th_weight': 0,
            'product_uos_qty': qty}, 'domain': {'product_uom': [],
               'product_uos': []}}
    if not date_order:
        date_order = time.strftime(DEFAULT_SERVER_DATE_FORMAT)

    result = {}
    warning_msgs = ''
    product_obj = product_obj.browse(cr, uid, product, context=context_partner)

    uom2 = False
    if uom:
        uom2 = product_uom_obj.browse(cr, uid, uom)
        if product_obj.uom_id.category_id.id != uom2.category_id.id:
            uom = False
    if uos:
        if product_obj.uos_id:
            uos2 = product_uom_obj.browse(cr, uid, uos)
            if product_obj.uos_id.category_id.id != uos2.category_id.id:
                uos = False
        else:
            uos = False
    fpos = fiscal_position and self.pool.get('account.fiscal.position').browse(cr, uid, fiscal_position) or False
    if update_tax:  # The quantity only have changed
        result['tax_id'] = self.pool.get('account.fiscal.position').map_tax(cr, uid, fpos, product_obj.taxes_id)      

    if not flag:
        result['name'] = self.pool.get('product.product').name_get(cr, uid, [product_obj.id], context=context_partner)[0][1]
        if product_obj.description_sale:
            result['name'] += '\n' + product_obj.description_sale
    domain = {}
    if (not uom) and (not uos):
        result['product_uom'] = product_obj.uom_id.id
        if product_obj.uos_id:
            result['product_uos'] = product_obj.uos_id.id
            result['product_uos_qty'] = qty * product_obj.uos_coeff
            uos_category_id = product_obj.uos_id.category_id.id
        else:
            result['product_uos'] = False
            result['product_uos_qty'] = qty
            uos_category_id = False
        result['th_weight'] = qty * product_obj.weight
        domain = {'product_uom':
                    [('category_id', '=', product_obj.uom_id.category_id.id)],
                    'product_uos':
                    [('category_id', '=', uos_category_id)]}
    elif uos and not uom:  # only happens if uom is False
        result['product_uom'] = product_obj.uom_id and product_obj.uom_id.id
        result['product_uom_qty'] = qty_uos / product_obj.uos_coeff
        result['th_weight'] = result['product_uom_qty'] * product_obj.weight
    elif uom:  # whether uos is set or not
        default_uom = product_obj.uom_id and product_obj.uom_id.id
        q = product_uom_obj._compute_qty(cr, uid, uom, qty, default_uom)
        if product_obj.uos_id:
            result['product_uos'] = product_obj.uos_id.id
            result['product_uos_qty'] = qty * product_obj.uos_coeff
        else:
            result['product_uos'] = False
            result['product_uos_qty'] = qty
        result['th_weight'] = q * product_obj.weight  # Round the quantity up

    if not uom2:
        uom2 = product_obj.uom_id
    # get unit price

    if not pricelist:
        warn_msg = _('You have to select a pricelist or a customer in the sales form !\n'
                'Please set one before choosing a product.')
        warning_msgs += _("No Pricelist ! : ") + warn_msg + "\n\n"
    else:
        price = self.pool.get('product.pricelist').price_get(cr, uid, [pricelist],
                product, qty or 1.0, partner_id, {
                    'uom': uom or result.get('product_uom'),
                    'date': date_order,
                    })[pricelist]
        if price is False:
            warn_msg = _("Cannot find a pricelist line matching this product and quantity.\n"
                    "You have to change either the product, the quantity or the pricelist.")

            warning_msgs += _("No valid pricelist line found ! :") + warn_msg + "\n\n"
        else:
            result.update({'price_unit': price})   

    cr.execute("select s.expr_date from stock_move s where s.product_id= %s", (product,))     
    date_all=[]
    data=cr.fetchall()     
    print data
    for date in data:                   
        date_all.append((' ',date))
        result.update({'expr_date':date_all})    
    print 'Expr Date is ..................',result

    if warning_msgs:
        warning = {
                   'title': _('Configuration Error!'),
                   'message' : warning_msgs
                }

    return {'value':result, 'domain': domain, 'warning': warning}