Multiple upload class

I need to upload more than 1 file to the server and I look around web and found out it can be done with arrays, I use the fallowing code:

add_movie.php:
<?php
$max_file_size = 1048576;
if(isset($_POST['submit'])) {
$movie = new Movie();
$n = 2;//nr of files
for($i=1; $i<=$n; $i++) {
$movie->attach_file($_FILES['file']);
}
if($movie->save($id=NULL)) {

// Success
$session->message("Movie uploaded successfully.");
redirect_to('movies.php');
} else {
// Failure
$message = join("<br />", $movie->errors);
}
}
?>
<form action="add_movie.php" enctype="multipart/form-data" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="<?php echo $max_file_size; ?>" />
<input type="file" name="file[]" size="70" />
<input type="file" name="file[]" value="" size="70" />
<input type="submit" name="submit" value="Add Movie" size="70" />
</form>

movie.php //class

public function attach_file($file) {

// Perform error checking on the form parameters
if(!$file || empty($file) || !is_array($file)) {
// error: nothing uploaded or wrong argument usage
$this->errors[] = "No file was uploaded.";
return false;
} elseif($file['error'] != 0) {

// error: report what PHP says went wrong
$this->errors[] = $this->upload_errors[$file['error']];
return false;
} else {

// Set object attributes to the form parameters.
$this->temp_path = $file['tmp_name'];
$this->poster = basename($file['name']);
$this->poster_type= $file['type'];
$this->poster_size= $file['size'];

return true;
}
}

public function save($id=NULL, $ok=NULL) {

// Can't save if there are pre-existing errors
if(!empty($this->errors)) { return false; }

$n=2;
if(isset($ok)) {
for($i=1; $i<=$n; $i++) {
// Can't save without filename and temp location
if(empty($this->file[$i]) || empty($this->temp_path[$i])) {
$this->errors[$i][] = "The file location was not available.";
return false;
}

// Determine the target_path
$target_path = SITE_ROOT .DS. 'public' .DS. $this->upload_dir .DS. $this->file[$i];

// Make sure a file doesn't already exist in the target location
if(file_exists($target_path)) {
$this->errors[$i][] = "The file {$this->file[$i]} already exists.";
return false;
}

// Attempt to move the file
if(move_uploaded_file($this->temp_path, $target_path)) {

// Success
// Save a corresponding entry to the database
if(!isset($id)) {
if($this->create()) {

// We are done with temp_path, the file isn't there anymore
unset($this->temp_path);
return true;
}
} else {
// We are done with temp_path, the file isn't there anymore
unset($this->temp_path);
return true;
}
} else {

// File was not moved.
$this->errors[$i][] = "The file upload failed, possibly due to incorrect permissions on the upload folder.";
return false;
}
}
} else {
return true;
}
}
public function image_path($i=1) {
return $this->upload_dir."/".$this->file[$i];
}

This is a part of the code, I didn't put it all because it is big and hard to fallow. I believe that the problem is at function attach_file, I need somehow to run the function for every file, I tried using arrays but I failed. Can anyone please help me ?

PS: Sorry for my grammar, it's not my native language, Thank you.