13.金钱不够两位小数点，保留两位小数

<wxs module="we">
    var toFixed = function (value) {
        if(value){
            value = Number(value)
            return value.toFixed(2);
        }else{
            return 0
        }
    }
    module.exports = {
        toFixed :toFixed
    }
</wxs>

{{we.toFixed(all_pay)}}