js 身份证校验代码

var _checkIDCard = function(d){
 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"};
 var sId = d;
 var iSum = 0;
 var info = "";
 if(sId.length !== 18){
  return "证件号码长度必须为18位！"
 }
 if(!/^\d{17}(\d|x|X)$/i.test(sId)){
  return "证件号码格式错误!";
 }
 sId = sId.replace(/x$/i, "a");
 if (aCity[parseInt(sId.substr(0, 2))] === null){
  return "证件号码地区不对！";
 }
 sBirthday = sId.substr(6, 4) + "-" + Number(sId.substr(10, 2)) + "-"
   + Number(sId.substr(12, 2));
 var d = new Date(sBirthday.replace(/-/g, "/"));
 if (sBirthday != (d.getFullYear() + "-" + (d.getMonth() + 1) + "-" + d
   .getDate())){
  return "证件号码出生日期非法！";
 }
 for (var i = 17; i >= 0; i--)
  iSum += (Math.pow(2, i) % 11) * parseInt(sId.charAt(17 - i), 11);
 if (iSum % 11 != 1)
  return "证件号码输入非法！";
 // aCity[parseInt(sId.substr(0,2))]+","+sBirthday+","+(sId.substr(16,1)%2?"男":"女");//此次还可以判断出输入的身份证号的人性别
 
 return ""; 
}