$('.chatUsuariosLista').click(function() {
            idUsuario = this.id;
            $("#chatMsg").load('inc_chatMensagens.php?de='+idUsuario+'&para='+$("#para").val());
            $("#para").val(idUsuario);

            $('#chat2').attr({scrollTop: $('#chat2').attr('scrollHeight')});

        });

<div id="chat2">
    <ul>
        <?php while ($row = $rs->fetch_assoc()) {?>

            <?php if ($_GET['de'] == $row['de']) {?>
                <li>
                    <div class="bubble">
                        <span class="personName">Cliente:</span> <br>
                        <span class="personSay"><?php echo $row['msg']; ?></span> <br>
                        <span class="time"><?php echo $row['data']; ?></span>
                    </div>
                </li>
            <?php }else{ ?>
                <li>
                    <div class="bubble2">
                        <span class="personName2">Você:</span> <br>
                        <span class="personSay2"><?php echo $row['msg']; ?></span><br>
                        <span class="time2"><?php echo $row['data']; ?></span>
                    </div>
                </li>
            <?php } ?>

        <?php } ?>
    </ul>
</div>