在使用复选框删除数据之前，我希望显示确认消息

在删除数据之前，我在显示确认消息时遇到问题

if(isset($_POST['del'])){
        echo "
            <script>
                var x;
                    x = confirm ('You want to proceed deleting?');
                    if(x == true){";
            for($i=0;$i<$_SESSION['count'];$i++){
            $checkbox = $_POST['checkbox'];
            $del_id = $checkbox[$i];
            $query = mysql_query("SELECT picture FROM tblreserve WHERE id='$del_id'");
            while($row = mysql_fetch_assoc($query)){
                $del_pic = $row['picture'];
            }
            $sql = "DELETE FROM tblreserve WHERE id = $del_id";
            $result = mysql_query($sql);
            if($result){
                if(is_file($del_pic)){
                        unlink($del_pic);
            }
    }
    }
    header('location:view.php');
                    echo "}
                    else{
                        location.href = 'view.php';
                        }
                    </script>";
    }