制保留2位小数

//制保留2位小数，如：2，会在2后面补上00.即2.00function 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;}