验证身份证合法性的js-白红宇

分别对15和18位的身份证号进行验证，非常严格。
function idCardNo(value){  //验证身份证号方法  var area = { 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: "xinjiang", 71: "台湾", 81: "香港", 82: "澳门", 91: "国外" }  var idcard, Y, JYM;  var idcard=value;  var S, M;  var idcard_array = new Array();  idcard_array = idcard.split("");  if (area[parseInt(idcard.substr(0, 2))] == null) return false;  switch (idcard.length) {      case 15:          if ((parseInt(idcard.substr(6, 2)) + 1900) % 4 == 0 || ((parseInt(idcard.substr(6, 2)) + 1900) % 100 == 0 && (parseInt(idcard.substr(6, 2)) + 1900) % 4 == 0)) {              ereg = /^[1-9][0-9]{
   5}[0-9]{
   2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{
   3}$/; //测试出生日期的合法性          }          else {              ereg = /^[1-9][0-9]{
   5}[0-9]{
   2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{
   3}$/; //测试出生日期的合法性          }          if (ereg.test(idcard))              //return Errors[0];            var res = true;          else              //return Errors[2];            var res = false;          return res;          break;      case 18:          if (parseInt(idcard.substr(6, 4)) % 4 == 0 || (parseInt(idcard.substr(6, 4)) % 100 == 0 && parseInt(idcard.substr(6, 4)) % 4 == 0)) {              ereg = /^[1-9][0-9]{
   5}19[0-9]{
   2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{
   3}[0-9Xx]$/; //闰年出生日期的合法性正则表达式          }          else {              ereg = /^[1-9][0-9]{
   5}19[0-9]{
   2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{
   3}[0-9Xx]$/; //平年出生日期的合法性正则表达式          }          if (ereg.test(idcard)) {              S = (parseInt(idcard_array[0]) + parseInt(idcard_array[10])) * 7 + (parseInt(idcard_array[1]) + parseInt(idcard_array[11])) * 9 + (parseInt(idcard_array[2]) + parseInt(idcard_array[12])) * 10 + (parseInt(idcard_array[3]) + parseInt(idcard_array[13])) * 5 + (parseInt(idcard_array[4]) + parseInt(idcard_array[14])) * 8 + (parseInt(idcard_array[5]) + parseInt(idcard_array[15])) * 4 + (parseInt(idcard_array[6]) + parseInt(idcard_array[16])) * 2 + parseInt(idcard_array[7]) * 1 + parseInt(idcard_array[8]) * 6 + parseInt(idcard_array[9]) * 3;              Y = S % 11;              M = "F";              JYM = "10X98765432";              M = JYM.substr(Y, 1);              if (M == idcard_array[17])                  //return Errors[0];                var res = true;              else                  //return Errors[3];                var res = false;          }          else              //return Errors[2];            res = false;          return res;          break;      default:          res = false;          return res;          break;    };}