//保留两位小数             //功能：将浮点数四舍五入，取小数点后2位            function toDecimal(x) {                var f = parseFloat(x);                if (isNaN(f)) {                    return;                }                f = Math.round(x*100)/100;                return f;            }    

        //制保留2位小数，如：2，会在2后面补上00.即2.00            function toDecimal2(x) {                var f = parseFloat(x);                if (isNaN(f)) {                    return false;                }                var f = Math.round(x*100)/100;                var s = f.toString();                var rs = s.indexOf(‘.‘);                if (rs < 0) {                    rs = s.length;                    s += ‘.‘;                }                while (s.length <= rs + 2) {                    s += ‘0‘;                }                return s;            }