Adding ispostback to javascript

My asp.net uses the datepicker feature. When using traditional inputs, this script added the datepicker feature
    <script type="text/javascript">
    $(function() {
        $( "#meetingdate" ).datepicker({ maxDate: +0,onSelect:function(){}});

    });    
    
    $('#meetingdate').datepicker({
                maxDate: +0,
                onSelect:
                    function (dateText, inst) {
                        $('#meetingdate').trigger('ch ...