function decimal(x) { var f = parseFloat(x); if (isNaN(f)) { alert("请输入数字!"); return; } 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; }