function isCardID(sId){ 
  var iSum=0 ; 
  var info="" ; 
  if(!/^\d{17}(\d|x)$/i.test(sId)) return "你输入的身份证长度或格式错误"; 
  sId=sId.replace(/x$/i,"a"); 
  if(aCity[parseInt(sId.substr(0,2))]==null) return "你的身份证地区非法"; 
  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 "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(sId.charAt(17 - i),11) ; 
  if(iSum%11!=1) return "你输入的身份证号非法"; 
  return true;//aCity[parseInt(sId.substr(0,2))]+","+sBirthday+","+(sId.substr(16,1)%2?"男":"女")  
} 
[/code]