update_summary: function(){
            var order = this.pos.get('selectedOrder');
            var total     = order ? order.getTotalTaxIncluded() : 0;
            var taxes     = order ? total - order.getTotalTaxExcluded() : 0;
            var discount = 0;
            var discount_id = self.$('#discount-card-select').val();
            if (discount_id){

                 var discount_card = new module.PaymentScreenDiscountWidget(this, {});
        var discont_line = discount_card.fetch('pos.discount.cards',['type', 'value'],[['id','=', discount_id]])
            .then(function(discount_val)
            {
                var type =  discount_val[0].type;
                var value = discount_val[0].value;
                if (type === 'fi'){
                     discount  = value;
                }
                else{
                    discount  = value;
                }
                console.log("discount value.........................",value)
            });



            }


            console.log("discount value fianl....................val",discount);
            this.el.querySelector('.summary .total > .value').textContent = this.format_currency(total);
            this.el.querySelector('.summary .total .subentry .value').textContent = this.format_currency(taxes);
            this.el.querySelector('.summary .total .discount .value').textContent = this.format_currency(discount);

        },