ID Card Verification

function Checkidcard (ID) {
var result=null;
var regExp =/^[a-za-z][0-9]{6}\ ([\w]{1}\) $/; Used to match Hong Kong identity card
if (id.length = = 15) {
Result=id.match (' \^ (11|12|31|51|15|65|54|64|45|81|82|23|22|21|13|14|63|37|41|32|34|35|36|43|42|44|46|62|61|51| 52|53|71|33|50) \\d{13}$ ');
if (Null==result) {
Return ' ID number is wrong! ';
}
return null;
} else if (id.length = = 18) {
Result=id.match ("\^ (11|12|31|51|15|65|54|64|45|81|82|23|22|21|13|14|63|37|41|32|34|35|36|43|42|44|46|62|61|51| 52|53|71|33|50) \\d{15}[xx0-9]$ ");
if (Null==result) {
Return ' ID number is wrong! ';
}

var check = 0;
var checknum = new Array (2, 4, 8, 5, 10, 9, 7, 3, 6, 1, 2, 4, 8, 5, 10, 9, 7);
var checkNum2 = new Array ("1", "0", "X", "9", "8", "7", "6", "5", "4", "3", "2");
for (var i = 0; i <; i++) {
Check + = id.substring (16-i,17-i) * Checknum[i];
}
if (checknum2[(check%)]!=id.substring (17,18)) {
Return ' ID number is wrong! ';
}
return null;
}else if (regexp.test (ID)) {
return null
}
else {
Return ' ID number is wrong! ';
}
}

/**
* @ ID number Birthday Year
* 421022198810064521 = 1988
* 421022881006452 = 1988
*/
function Getbirthdayyearfromidcard (idcard) {
if (Idcard = = undefined) {
return null;
}
if (idcard.length = = 15) {
Return "+" + idcard.substring (6, 8);
}
if (idcard.length = = 18) {
Return idcard.substring (6, 10);
}
return null;
}

/**
* @ ID number Birthday Month
* 421022198810064521 = 10
* 421022881006452 = 10
*/
function Getbirthdaymonthfromidcard (idcard) {
if (Idcard = = undefined) {
return null;
}
if (idcard.length = = 15) {
Return Idcard.substring (8, 10);
}
if (idcard.length = = 18) {
Return Idcard.substring (10, 12);
}
return null;

}

/**
* @ ID number Birthday Month
* 421022198810064521 = 10
* 421022881006452 = 10
*/
function Getbirthdaydayfromidcard (idcard) {
if (Idcard = = undefined) {
return null;
}
if (idcard.length = = 15) {
Return Idcard.substring (10, 12);
}
if (idcard.length = = 18) {
Return Idcard.substring (12, 14);
}
return null;

}

/**
* @ ID number and birthday validation
*/
function Checkidcardandbirthday (Idcard, birthday) {
var idcardresult = Checkidcard (Idcard);
if (Idcardresult = = NULL && Birthday! = ") {
var yearfromidcard = Getbirthdayyearfromidcard (Idcard);
var monthfromidcard = Getbirthdaymonthfromidcard (Idcard);
var dayfromidcard = Getbirthdaydayfromidcard (Idcard);
var birthday_year = birthday.substring (0, 4);
var birthday_month = birthday.substring (5, 7);
var birthday_day = birthday.substring (8, 10);
if (yearfromidcard! = birthday_year) {
Return "The year of birth does not match the identity card. ";
}
if (monthfromidcard! = birthday_month) {
Return "The month of birth does not match the identity card. ";
}
if (dayfromidcard! = birthday_day) {
Return "date of birth is inconsistent with identity card. ";
}
}
return null;
}

ID Card Verification