hellow , How to write code html ,css and javascript for valdation id number by this code:

Note: I need two fields of the same type. Also, how do I make the verification result appear as text below the field and not in the alert()?

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/**

* @return {number}

*/

function validateSAID(id) {

id = id.trim();

if (isNaN(parseInt(id))) {

return -1;

}

if (id.length !== 10) {

return -1;

}

const type = id.substr(0, 1);

if (type !== '2' && type !== '1') {

return -1;

}

var sum = 0;

for (var i = 0; i < 10; i++) {

if (i % 2 === 0) {

const ZFOdd = String('00' + String(Number(id.substr(i, 1)) * 2)).slice(-2);

sum += Number(ZFOdd.substr(0, 1)) + Number(ZFOdd.substr(1, 1));

} else {

sum += Number(id.substr(i, 1));

}

}

return (sum % 10 !== 0) ? -1 : type;

}