python - How to use a field to appear in the dropdown of many2one? -

please me when using many2one have combo product names, question how change content of combo , ie instead of product have identifier.

thank you

class saisir.soumission(osv.osv)       _columns = {         'numoffre' : fields.char('n° offre'), # want use field apear in many2one         'organisme_s' : fields.char('organisme'),         'taxe' : fields.selection([('12','12 %'),('10','10 %')],'taxe etablissement'),          'observation_s' : fields.text('observation'),         'order_line' : fields.one2many('saisir.soumission.ligne','order_id','soumission_id')         }  class saisir_soumission_ligne(osv.osv):     _name ='saisir.soumission.ligne'      def on_change_produit(self, cr, uid, ids, product_id):         val = {}         prod = self.pool.get('product.product').browse(cr, uid, product_id)         if prod:             val['prix'] = prod.list_price             val['garantie'] = prod.warranty         return {'value': val}      _columns= {        'order_id': fields.many2one('saisir.soumission', 'order reference'),        'product_id' : fields.many2one('product.product', 'type engin'),        'marque' : fields.char('marque'),        'prix' : fields.float('prix unitaire'),        } 

set _rec_name 'numoffre' in model this

class saisir.soumission(osv.osv)      _rec_name = 'numoffre'      _columns = {         'numoffre' : fields.char('n° offre'), # want use field apear in many2one         'organisme_s' : fields.char('organisme'),         'taxe' : fields.selection([('12','12 %'),('10','10 %')],'taxe etablissement'),          'observation_s' : fields.text('observation'),         'order_line' : fields.one2many('saisir.soumission.ligne','order_id','soumission_id')     }