<div class="panel panel-default">
               <div class="panel-heading"><h4>My Messages</h4></div>
                <div class="panel-body">
                 <h4 style='text-decoration: underline; color:#000'>Messages:</h4>

<script>

????

</script



                <?php include_once('pm/pm_open.php'); ?>
                </div><!--/panel-body-->
             </div><!--/panel-->

<?php
 $usid = $_SESSION['user_id'];

                    $dbh = new PDO('mysql:host=127.0.0.1;dbname=login','root','');
                    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$sql="SELECT * FROM `pm` WHERE `user1` = :user1 or `user2` = :user2 ORDER BY time ASC ";
$stmt=$dbh->prepare($sql);
$stmt->bindValue(':user1', $usid, PDO::PARAM_INT);
$stmt->bindValue(':user2', $from, PDO::PARAM_INT);
$stmt->execute();
if ($stmt->rowCount() > 0) {
$result = $stmt->fetchAll();
}
foreach( $result as $row) {
$post_id = $row['id'];
$from = $row['user2'];
$to = $_row['user1'];
$time = $row['time'];
$message = $row['message'];

echo "<br /><div style='background-color:black; color:white'><p style='width:70%; margin:auto'>From: <a href='profile.php?id=".$from."'>User #".$from."</a><br />".$message."           <br /> @ ".$time."<br /></p>
            <form>
            <input type='button' id='delete' class='btn-xs btn-danger' value='Delete'>
            </form>
            </div>";

}

if(isset($_POST['delete'])){


                $STH = $dbh->prepare("DELETE FROM pm WHERE id = :id");
                $STH->bindParam(':id', $post_id);
                $STH->execute();


                echo "<br ><p style='background-color:black; text-align:center; color:Red'>Message Deleted Successfully<p>";
    }

<script>
var _delete = document.getElementById("delete");
_delete.onClick=function(){
 ????
};
</script>