function isIdCardNo(num) {
num = num.toUpperCase();
//身份證號碼為15位或者18位，15位時全為數字，18位前17位為數字，最後一位是校驗位，可能為數字或字元X。 
if (!(/(^\d{15}$)|(^\d{17}([0-9]|X)$)/.test(num))) {
alert('輸入的身份證號長度不對，或者號碼不符合規定！\n15位號碼應全為數字，18位號碼末位可以為數字或X。'); 
return false;
}

var len, re;
len = num.length; 
if(len == 15) {
re = new RegExp(/^(\d{6})(\d{2})(\d{2})(\d{2})(\d{3})$/); 
var arrSplit = num.match(re); 
var dtmBirth = new Date('19' + arrSplit[2] + '/' + arrSplit[3] + '/' + arrSplit[4]);
var bGoodDay;
alert(dtmBirth.getYear());
alert(Number(arrSplit[2]));
alert(dtmBirth.getMonth());
alert(Number(arrSplit[3]));
alert(dtmBirth.getDate());
bGoodDay = (dtmBirth.getYear() == Number(arrSplit[2])) && ((dtmBirth.getMonth() + 1) == Number(arrSplit[3])) && (dtmBirth.getDate() == Number(arrSplit[4])); 
if (!bGoodDay) {
alert('輸入的身份證號裡出生日期不對！');
return false; 
} else {
//將15位身份證轉成18位 
//校驗位按照ISO 7064:1983.MOD 11-2的規定生成，X可以認為是數字10。
var arrInt = new Array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);
var arrCh = new Array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'); 
var nTemp = 0, i;
num = num.substr(0, 6) + '19' + num.substr(6, num.length - 6);
for(i = 0; i < 17; i ++) {
nTemp += num.substr(i, 1) * arrInt[i]; 
}
num += arrCh[nTemp % 11];
return num;  


}
} else if(len == 18) {
re = new RegExp(/^(\d{6})(\d{4})(\d{2})(\d{2})(\d{3})([0-9]|X)$/);
var arrSplit = num.match(re); 
//檢查生日日期是否正確 
var dtmBirth = new Date(arrSplit[2] + "/" + arrSplit[3] + "/" + arrSplit[4]);
var bGoodDay; 
alert(dtmBirth.getYear());
alert(dtmBirth.getMonth());
alert(dtmBirth.getDate());
bGoodDay = (dtmBirth.getFullYear() == Number(arrSplit[2])) && ((dtmBirth.getMonth() + 1) == Number(arrSplit[3])) && (dtmBirth.getDate() == Number(arrSplit[4]));
if (!bGoodDay) {
alert(dtmBirth.getYear()); 
alert(arrSplit[2]); 
alert('輸入的身份證號裡出生日期不對！'); 
return false; 
} else {
//檢驗18位身份證的校驗碼是否正確。
//校驗位按照ISO 7064:1983.MOD 11-2的規定生成，X可以認為是數字10。
var valnum;
var arrInt = new Array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);
var arrCh = new Array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'); 
var nTemp = 0, i; 
for(i = 0; i < 17; i ++) {
nTemp += num.substr(i, 1) * arrInt[i]; 
}
valnum = arrCh[nTemp % 11]; 
if (valnum != num.substr(17, 1)) {
alert('18位身份證的校驗碼不正確！應該為：' + valnum);
return false; 
}
return num; 
}
}
return false; 

}