JavaScript之保留两位小数

        if (!isNumeric(fm.ChangeFee.value)) {
            alert("请输入正确的变更费用");
            document.getElementsByName('ChangeFee')[0].style.borderColor = "#f64f4f";
            return false;
        }

        var string = fm.ChangeFee.value.toString();
        var index = string.indexOf(".");
        if (index > -1) {
            var pointB = parseInt(string.substring(0, index));
            var pointA = parseInt(string.substring(index + 1, string.length));
            if (index > 10 || getStrByte(pointA.toString()) > 2) {
                alert("变更费用长度限制为10位整数，2位小数");
                document.getElementsByName('ChangeFee')[0].style.borderColor = "#f64f4f";
                return false;
            }
        } else if (getStrByte(string) > 10) {
            alert("变更费用字符长度限制为10位整数，2位小数");
            document.getElementsByName('ChangeFee')[0].style.borderColor = "#f64f4f";
            return false;
        }

function isNumeric(sNumer) {
    var RegChkExp = /^(\+?)(\-?)(\d+)(\.\d+)?$/;
    return RegChkExp.test(sNumer);
}