<script>
        var user_id = document.getElementById("user_id").innerHTML;
        var date  = new Date;
        var month = date.getMonth();
        month++;
        var request = new XMLHttpRequest();
        request.open('GET','send_table_data.php?user_id=' + user_id, true);
        request.send();

        request.onreadystatechange = function(){
            while (request.readyState != 4){
                    return;
            }
            if(request.status != 200){
                    alert (request.status + ':' + request.statusText);
                }else{
                    var mas = JSON.parse(request.responseText);
                    alert (mas.month + " " + mas.comments[0]);
                }
        };
</script>

<?php
require "database_connection.php";
require "current_date.php";
$user_id = $_REQUEST("user_id");
require "get_table_data.php";
 $array_of_data = array(
                        "month"    => $month_num,
                        "dates"    => $dates,
                        "hours"    => $hours,
                        "comments" => $comments);
  echo json_encode($array_of_data);