Javascript 按最小5分进位函数

     //type:0: nearest
    //     1: rounding down
    //     2: rounding up
// amountOld: money 数值；
//type: 0 为靠近进位， 1：为下进位； 2：向上取
//return: 处理后的数值
    function GetNearAmount(amountOld, type) {
        var curChange = amountOld * 100;
        if (amountOld < 0)
            curChange = 0 - curChange;
        var curMoneyRounding = 5;
        var curChangeRoundingAmount=0;

        var curRemainder = curChange % curMoneyRounding;

        if (type == 0) {
            if (curRemainder > curMoneyRounding / 2)
                curChangeRoundingAmount = curMoneyRounding - curRemainder
            else
                curChangeRoundingAmount = 0 - curRemainder

            if (amountOld < 0)
                curChangeRoundingAmount = 0 - curChangeRoundingAmount;
        }
        else if (type == 1) {
            curChangeRoundingAmount = 0 - curRemainder;
        }
        else if (type == 2) {
            curChangeRoundingAmount = curMoneyRounding - curRemainder;
        }
        
        var workout_change_rounding_amount = 0 - (curChangeRoundingAmount / 100)
        return workout_change_rounding_amount;
    }