**As follows: **

var aCity={11:" Beijing ",12:" tianjin ",13:" hebei ",14:" shanxi ",15:" Inner Mongolia ", 
21:" liaoning ",22:" Ji Lin ",23:" heilongjiang ",31:" Shanghai ",32:" jiangsu ",33:" zhejiang ", 
34:" anhui ",35:" fujian ",36:" jiangxi ",37:" shandong ",41:" henan ",42:" hubei ", 
43:" hunan ",44:" guangdong ",45:" guangxi ",46:" hainan ",50:" chongqing ",51:" sichuan " 
,52:" guizhou ",53:" yunnan ",54:" Tibet ",61:" shaanxi ",62:" gansu ",63:" qinghai ", 
64:" ningxia ",65:" xinjiang ",71:" Taiwan ",81:" Hong Kong ",82:" Macau ",91:" foreign "}  

 
function isCardID(sId){ 
  var iSum=0 ; 
  var info="" ; 
  if(!/^d{17}(d|x)$/i.test(sId)) return " The length or format of the id card you entered is wrong "; 
  sId=sId.replace(/x$/i,"a"); 
  if(aCity[parseInt(sId.substr(0,2))]==null) return " Your id card is illegal "; 
  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 " The date of birth on the identity card is illegal "; 
  for(var i = 17;i>=0;i --) iSum += (Math.pow(2,i) % 11) * parseInt(sId.charAt(17 - i),11) ; 
  if(iSum%11!=1) return " The id number you entered is illegal "; 
  return true;//ACity [parseInt (sId) substr (0, 2))) + ", "+ sBirthday +", "+ (sId) substr (16, 1) % 2?" Male ":" female ")    
}