cart bug

<?php
function cart(){


    global $conn;






    foreach ($_SESSION as $name => $value) {
        if($value > 0){

        if(substr($name, 0, 8 ) == "product_"){
            $length = strlen($name) -8;
            $item_id = substr($name,8 , $length);



    $query = "SELECT * FROM gallery2 WHERE id =".escape_string($item_id)."";
    $run_item = mysqli_query($conn,$query);
    while($rows = mysqli_fetch_assoc($run_item)){
///////////////////////////////starts//////////////////////////////////////////
                $vari = $rows['variante'];
                $num = $rows['title'];
                $id = $rows['id'];
                $btn_add='<a class="btn btn-success" href="cart.php?add='.$id.'"><i class="fa fa-plus fa-lg" aria-hidden="true" add_btn></i></a>';
                $btn_remove = '<a class="btn btn-warning" href="cart.php?remove='.$id.'"><i class="fa fa-minus fa-lg" aria-hidden="true" remove_btn></i></a>';
                $btn_delete='<a class="btn btn-default delete_btn" href="cart.php?delete='.$id.'"><i class="fa fa-times fa-lg" aria-hidden="true"></i></a>';

                if($vari < 1){
              $product = '<tr>
              <td>Estampa</td>
              <td>'.$num.'</td>
                <td><select name="estado" class="form-control selectpicker" required="">
                <option value="" required="">Selecione o tecido</option>


                </select>
                </td>
              <td>'.$value.'</td>
              <td>R$100,00</td>
              <td>sub.total</td>
              <td>
              '.$btn_add.' '.$btn_remove.' '.$btn_delete.'

              </td>
              </tr>';
              echo $product;
                }else{
                    $product = '<tr>
              <td>Estampa</td>
              <td>'.$num.'-'.$vari.'</td>
              <td></td>
              <td>'.$value.'</td>
              <td>R$100,00</td>
              <td>sub.total</td>
              <td>'.$btn_add.' '.$btn_remove.' '.$btn_delete.'</td>
              </tr>';
              echo $product;
                }

 ///////////////////////////////ends/////////////////////////////////////////


    }

        }


        }

    }

}
?>