problem with a domain (many2one)

Hi again, I need do a filter in a selection field, this is the code: 'wpartner_id': fields.related('incidencia_id', 'partner_id', type="many2one", relation="res.partner", string="Cliente", store=False), 'presupuesto': fields.many2one('sale.order', 'Presupuesto', ondelete='cascade', domain=[('partner_id', '=', wpartner_id)]), This return this error: 'presupuesto': fields.many2one('sale.order', 'Presupuesto', ondelete='cascade', domain=[('partner_id', '=', wpartner_id)]), NameError: name 'wpartner_id' is not defined I need some help to solve it, please Thanks