Mask TextBox: Automatically add hyphen (dash) after two digits in TextBox using jQuery

Hi makumbi,

Please refer below sample example. 

HTML

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
    $(function () {
        $('[id*=txtData]').on('keypress', function () {
            var number = $(this).val();
            if (number.length == 2) {
                $(this).val($(this).val() + '-');
            }
        });
    });
</script>
<asp:TextBox runat="server" ID="txtData" MaxLength="5" />

Screenshot