function CheckSocialNo(no1, no2)
{
    var i;
    var val0, val1, val2, val3, val4, val5, val6, val7, val8, val9, val10, val11, val12;
    var sum, checkno;
	var socialno = no1 + '' + + no2;

    if (socialno.length != 13)
        return false;

    for (i = 0; i < 13; i++) {
        if ((socialno.charAt(i) < '0') || (socialno.charAt(i) > '9'))
            return false;
    }

    if ((socialno.charAt(6) < '1') || (socialno.charAt(6) > '4'))
        return false;

    month = parseInt(socialno.charAt(2))*10 + parseInt(socialno.charAt(3))
    day = parseInt(socialno.charAt(4))*10 + parseInt(socialno.charAt(5))
    if ((month == 1) || (month == 3) || (month == 5) || (month == 7) || (month == 8) || (month == 10) || (month == 12)) {
        if ((day < 0) || (day > 31))
            return false;
    }
    if ((month == 2)) {
        if ((day < 0) || (day > 29))
            return false;
    }
    if ((month == 4) || (month == 6) || (month == 9) || (month == 11)) {
        if ((day < 0) || (day > 30))
            return false;
    }

    val0  = parseInt(socialno.charAt(0)) * 2;
    val1  = parseInt(socialno.charAt(1)) * 3;
    val2  = parseInt(socialno.charAt(2)) * 4;
    val3  = parseInt(socialno.charAt(3)) * 5;
    val4  = parseInt(socialno.charAt(4)) * 6;
    val5  = parseInt(socialno.charAt(5)) * 7;
    val6  = parseInt(socialno.charAt(6)) * 8;
    val7  = parseInt(socialno.charAt(7)) * 9;
    val8  = parseInt(socialno.charAt(8)) * 2;
    val9  = parseInt(socialno.charAt(9)) * 3;
    val10  = parseInt(socialno.charAt(10)) * 4;
    val11  = parseInt(socialno.charAt(11)) * 5;
    val12  = parseInt(socialno.charAt(12));

    sum = val0 + val1 + val2 + val3 + val4 + val5 + val6 + val7 + val8 + val9 + val10 + val11;

    checkno = (11 - (sum % 11)) % 10;
    if (checkno == val12) {
        return true;
    }
    else {
        return false;
    }
}