SOURCE

function getId_no(){
var coefficientArray = [ "7","9","10","5","8","4","2","1","6","3","7","9","10","5","8","4","2"];// 加权因子
var lastNumberArray = [ "1","0","X","9","8","7","6","5","4","3","2"];// 校验码
var address = "420101"; // 住址
var birthday = "19810101"; // 生日
var s = Math.floor(Math.random()*10).toString() + Math.floor(Math.random()*10).toString() + Math.floor(Math.random()*10).toString();
var array = (address + birthday + s).split(""); 
var total = 0;
for(i in array){
total = total + parseInt(array[i])*parseInt(coefficientArray[i]);
} 
var lastNumber = lastNumberArray[parseInt(total%11)];
var id_no_String = address + birthday + s + lastNumber;
var x = document.getElementsByName("id_no");
for (var i = 0; i < x.length; i++) {
var o = x[i];
o.value = id_no_String;
}
}