validate check for social insurance number

validate check for social insurance number.

social insurance number: only 9 digits (1-9), only number, should be input in three boxes, 3 digit in each boxes( if possible use auto tab)

add the odd digits : means 1th,3dr,5th,7th, 9th digits together = odd digits sum value

Extract the even digits: mean 2nd, 4th, 6th, 8th digits-- and multiply by *2, add all the even digits together only if it is less than 10

if the 2nd, 4th, 6th, 8th digits is greater than 10 then , add like this ( for eg the 4th digit is 18 then add= 1+8)

Then,

odd digits sum value + the even digit sum value = multiple of ten (%10)

<!DOCTYPE >
<html>
<head>
<title></title>
</head>
<body>
	<script type="text/javascript">
		function Validation(sin)
		{
		    var num = sin.match(/^(\d{3})-?\d{3}-?\d{3}$/);
		    
		    var numDashes = sin.split('-').length - 1;
		    if (num == null || numDashes == 1) {
		        alert('Invalid S.I.N. Must be 9 digits or in the form NNN-NNN-NNN.');
		        msg = "does not appear to be valid";
		    }
		    else
		        if (parseInt(num[1], 10) == 0) {
		            alert("Invalid SIN: SIN's can't start with 000.");
		            msg = "does not appear to be valid";
		        }
		        else {
		            msg = "appears to be valid";
		            alert(sin + "\r\n\r\n" + msg + " Social Insurance Number.");
		        }
		
		         if (!num.test(sin)) return false;
		    sin = sin.split("-").join("");
		      var checksum=0;
		    for (var n = (2 - (sin.length % 2)); n <= sin.length; n += 2) {
		        checksum += parseInt(sin.chartAt(n - 1));
		        for (var n = (sin.length % 2) + 1; n < sin.length; n += 2)
		            var digit = parseInt(sin.charAt(n - 1)) * 2
		        if (digit < 10) {
		            checksum += digit;
		        }
		        else {
		            checksum += (digit - 9);
		        }
		    }
		    if ((checksum % 10) == 0) return true; else return false;
		    }
    
    </script>
	<form>
		<tt>
			SIN #: <input type="text" name="sin" size="11" maxlength="11" /> (use
			dashes!)
		</tt>
		<br />

</html>

Code is Not Working!!!

Can you sent me a Solution for this!!!