Update the query onbeforeunload and

This is my First Query when $_POST is set:

<?php
    if (isset($_POST['bags']))
{
    $bagS=$_POST['bags'];
        $id=$_POST["id"];
        $_SESSION['id']=$id;
        $cats = explode(" ", $bagS);
        $cats = preg_split('/,/', $bagS, -1, PREG_SPLIT_NO_EMPTY);
        foreach($cats as $key => $cat )
        {
        $cat  = mysqli_real_escape_string($con,$cats[$key]);
        $cat = trim($cat);
 if($cat !=NULL)
             {
                 $stmt = $con->prepare('UPDATE wallet SET `Status`="Hold" where `Id`=? AND `bags`="'.$cat.'" ');
                 $stmt->bind_param("s", $_POST["id"]);
                 $stmt->execute();

  }
  }
}

After that is set the script timeout to update next query if nothing happen from user side.

<script type="text/javascript">
          setTimeout(function() { window.location.href = "index.php?on_timeout=1"; }, 60 * 500);
</script>

Then script return query string when timeout and execute update query and redirect to other page:

if(isset($_GET['on_timeout'])) {

   echo  $bagS=$_SESSION['bags'];
   echo $id=$_SESSION['id'];
        $cats = explode(" ", $bagS);
        $cats = preg_split('/,/', $bagS, -1, PREG_SPLIT_NO_EMPTY);
        foreach($cats as $key => $cat )
        {
        $cat  = mysql_real_escape_string($cats[$key]);
        $cat = trim($cat);
 if($cat !=NULL)
             {
                  $stmt = $con->prepare('UPDATE wallet SET `Status`=" " where `Id`=? AND `bags`="'.$cat.'" AND `Status`="Hold" ');
                 $stmt->bind_param("s", $_SESSION['id']);
                 $stmt->execute();
                 echo "<script type='text/javascript'>location.href = 'cards.php';</script>";

  }
  }
}

 ?>

Now I want to execute the same query on when user close the browser or back the browser with the help of window.onbeforeunload, so please tell me how set the update code in this event.

<script>
var areYouReallySure = false;
    function areYouSure() {
    if(allowPrompt){
        if (!areYouReallySure && true) {
            areYouReallySure = true;
            var confMessage = "are you sure to do this";
            return confMessage;
        }
    }else{
        allowPrompt = true;
    }
}

var allowPrompt = true;
window.onbeforeunload = areYouSure;

</script>

You can call you code before leaving the page

function myfoo(){
         // Write your logic here
           $.ajax({
            url: "Pageurl_that_having_your_update_code",
            dataType: 'json',
            data: {
                on_timeout: 1
            },
            success: function (r) {}
});
    }

onbeforeunload:

 window.onbeforeunload = function(){
  myfoo();
  return 'Are you sure you want to leave?';
};

Or Jquery

$(window).bind('beforeunload', function(){
  myfoo();
  return 'Are you sure you want to leave?';
});