身份证验证js

function testCode(IDnumber){
var aCity = {
11 : "北京",
12 : "天津",
13 : "河北",
14 : "山西",
15 : "内蒙古",
21 : "辽宁",
22 : "吉林",
23 : "黑龙江",
31 : "上海",
32 : "江苏",
33 : "浙江",
34 : "安徽",
35 : "福建",
36 : "江西",
37 : "山东",
41 : "河南",
42 : "湖北",
43 : "湖南",
44 : "广东",
45 : "广西",
46 : "海南",
50 : "重庆",
51 : "四川",
52 : "贵州",
53 : "云南",
54 : "西藏",
61 : "陕西",
62 : "甘肃",
63 : "青海",
64 : "宁夏",
65 : "新疆",
71 : "台湾",
81 : "香港",
82 : "澳门",
91 : "国外搜索"
}
var error = "";
if (IDnumber == "") {
} else {
//验证身份证的格式
var iSum = 0;
var info = "";
if (!/^\d{17}(\d|x)$/i.test(IDnumber)) {
error = "输入的身份证长度或格式错误！";
}
IDnumber = IDnumber.replace(/x$/i, "a");
if (aCity[parseInt(IDnumber.substr(0, 2))] == null) {
error = "身份证地区非法！";
}
sBirthday = IDnumber.substr(6, 4) + "-"
+ Number(IDnumber.substr(10, 2)) + "-"
+ Number(IDnumber.substr(12, 2));
var d = new Date(sBirthday.replace(/-/g, "/"));
if (sBirthday != (d.getFullYear() + "-" + (d.getMonth() + 1) + "-" + d
.getDate())) {
error = "身份证上的出生日期非法！";
}
for ( var i = 17; i >= 0; i--)
iSum += (Math.pow(2, i) % 11)
* parseInt(IDnumber.charAt(17 - i), 11);
if (iSum % 11 != 1) {
error = "输入的身份证号非法！";
}
}
return error;
}