Не правильно работает цикл в php

for($i=0; $i<20; $i++){
    if($_FILES['img']['error'][$i]==0){
            $unical_id = time();
            $init_filename = $_FILES['img']['name'][$i];
            $file_extension = pathinfo($init_filename,PATHINFO_EXTENSION);
            $filename = $unical_id.'.'.$file_extension;
            move_uploaded_file($_FILES['img']['tmp_name'][$i], "uploads/$filename");
            $new_photo = "uploads/$filename";
        //echo $init_filename;
    };
}