Private Function ValidateNcode(ByVal NC As Int64) As Boolean
        If IsNumeric(NC) = False Or NC.ToString.Length < 10 Then
            Return False
        End If
        Dim vnc As String = NC.ToString
        Dim pos As Integer = 10
        Dim sum As Integer = 0

        For i = 0 To 8
            sum += Integer.Parse(vnc.ToCharArray()(i).ToString()) * pos
            pos = pos - 1
        Next i

        Dim remind As Integer = sum Mod 11
        Dim controlNum As Integer = Integer.Parse(vnc.ToCharArray()(9))

        If remind <= 2 Then
            If controlNum = remind Then
                Return True
            Else
                Return False
            End If
        Else
            If (11 - remind) = controlNum Then
                Return True
            Else
                Return False
            End If
        End If
    End Function

private bool ValidateNcode(Int64 NC)
{
if (IsNumeric(NC) == false | NC.ToString.Length < 10) {
return false;
}
string vnc = NC.ToString;
int pos = 10;
int sum = 0;

for (i = 0; i <= 8; i++) {
sum += int.Parse(vnc.ToCharArray()(i).ToString()) * pos;
pos = pos - 1;
}

int remind = sum % 11;
int controlNum = int.Parse(vnc.ToCharArray()(9));

if (remind <= 2) {
if (controlNum == remind) {
return true;
} else {
return false;
}
} else {
if ((11 - remind) == controlNum) {
return true;
} else {
return false;
}
}