Исправить добавление лишнего элемента в сессию

$title_web_site = mysql_fetch_array(mysql_query("SELECT * FROM `config` WHERE id='1'"));
ob_start();
switch($uri)
{
    case 1 : include("inc/index.php"); $content = "index"; break;
    case 2 : include("inc/catalog.php"); $content = "catalog"; break;
    case 3 : include("inc/product.php"); $content = "product"; break;
    case 4 : include("inc/about.php"); $content = "about"; break;
    case 5 : include("inc/contact.php"); $content = "contact"; break;
    case 7 : include("inc/pay.php"); $content = "pay"; break;
    default : echo "<script>window.location.href='/404'</script>";
}
ob_clean();
//В каждом файле есть переменная $title

<?
session_start();
if($_POST['button'])
    array_push($_SESSION['myCart'], 1);
    print_r($_SESSION['myCart']);
?>
<form method='post'>
    <input type='submit' name='button'>
</form>

$title = 'Contacts';
$content = 'My contacts.';

<title><?=$title?></title>
<div id="content">
<?=$content?>
</div>

<? 
    $myUrl = $_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
    $idUrl = explode('?', $_SERVER['REQUEST_URI']);
    $config = mysql_fetch_array(mysql_query("SELECT * FROM `config` WHERE id='1'"));
    if($config['url_method']=="ID"){
        $inf = mysql_fetch_array(mysql_query("SELECT * FROM `bd_all_t` WHERE `id`='".$idUrl[1]."'"));
    } else $inf = mysql_fetch_array(mysql_query("SELECT * FROM `bd_all_t` WHERE `chpu`='".urldecode($idUrl[1])."'"));
    
    $Keywords = $inf['name']." Купить товары ручной работы";
    $description = $inf['desc']."<!--это само описание товара-->";
    $config = mysql_fetch_array(mysql_query("SELECT `valute` FROM `config` WHERE id='1'"));
    switch ($config['valute']){
        case 'UAH' : $valuteRight=$config['valute']; break;
        case 'RUB' : $valuteRight=$config['valute']; break;
        case '€' : $valuteLeft=$config['valute']; break;
        case '$' : $valuteLeft=$config['valute']; break;
        }
    $title = $inf['name']." - ".$inf['category'];
    $keywords=$inf['Keyword'];
    $description='Купить '.$title.' в ..... '.$inf['desc'];
    if($inf['policy']=="")
        $statusPolicy = "false";
    
    if($_POST['go_to_cart_zakaz']){
        if($_POST['numb_zakaz']>0 && $_POST['numb_zakaz']<1000){
            if(isset($_SESSION['myCart'])){
                    for($i=0; $i<$_POST['numb_zakaz']; $i++)
                        array_push($_SESSION['myCart'], $inf['id']);
            }
            else
                $_SESSION['myCart']=array();
        } else echo '<Script>alert("Количество порций должно быть в диапазоне от 1 до 999!");</script>';
    }
?>
<form method='post'>
<div id='product_title'>
    <h1 id='product_title_label'><?=$inf['name'];?></h1>
</div>
<div id='product_title_footer'></div>
<div id='product_form_img'>
<img id='product_img' src='img/upload/700/<?=$inf['img_1'];?>.png'>
</div>
<a id='footer_name' style='margin-top: 11px;'>«<?=$inf['name'];?>»</a>
<p id='footer_name' style='font-size: 15px; color: #5B85FC; margin-left: 5px;margin-top: 11px;'>(<?=$inf['info'];?> гр.)</p>
<p id='footer_name' style='font-size: 40px; font-weight: bold; color: #5B85FB; margin-right: 0; margin-left: 40px;overflow: initial;'><?=$inf['price'];?></p>
<p id='footer_name' style='position: relative; top: 2px; color: #5B85FB;'><?=$valuteLeft?><?=$valuteRight?></p>
<div id='product_of_cart'><img style='width:13px;cursor: pointer;' onclick='minus();' src='img/m1.png'> 
<input onkeyup="this.value = this.value.replace (/\D/gi, '').replace (/^0+/, '');" maxlength='3' id='numb_product_cart' type='text' name='numb_zakaz' value='1'> шт. 
<img onclick='plus();' style='width:13px;margin-left:5px;cursor: pointer;' src='img/p1.png'></div>
<input type='submit' style='width: 110px;margin-left: 20px;' id='button_product' name='go_to_cart_zakaz' value='Заказать'>
<p id='product_desc'><?=$inf['desc'];?></p>
 
 
<script type="text/javascript">(function() {
  if (window.pluso)if (typeof window.pluso.start == "function") return;
  if (window.ifpluso==undefined) { window.ifpluso = 1;
    var d = document, s = d.createElement('script'), g = 'getElementsByTagName';
    s.type = 'text/javascript'; s.charset='UTF-8'; s.async = true;
    s.src = ('https:' == window.location.protocol ? 'https' : 'http')  + '://share.pluso.ru/pluso-like.js';
    var h=d[g]('body')[0];
    h.appendChild(s);
  }})();</script>
<div class="pluso" data-background="none;" data-options="medium,square,line,horizontal,nocounter,sepcounter=1,theme=14" data-services="vkontakte,odnoklassniki,facebook,twitter,google,moimir"></div>
<script>
    function minus(){
        if(document.getElementById('numb_product_cart').value>1)
          document.getElementById('numb_product_cart').value--;
    }
    function plus(){
        if(document.getElementById('numb_product_cart').value<999)
            document.getElementById('numb_product_cart').value++;
    }
</script>
</post>

# Константа для Include
define("CONST_RUFUS", true);
# Старт буфера
@ob_start();
switch($uri)
{
    case 1 : include("inc/index.php"); break;
    case 2 : include("inc/catalog.php"); break;
    case 3 : include("inc/product.php"); break;
    case 4 : include("inc/about.php");  break;
    case 5 : include("inc/contact.php"); break;
    case 7 : include("inc/pay.php");  break;
    default : echo "<script>window.location.href='/404'</script>";
}
$content = ob_get_contents();
 
# Очищаем буфер
ob_end_clean();