Amazon S3 Codeignitor Library

[eluser]businessman332211[/eluser]
I am referring to this library: http://www.haughin.com/code/s3/

How do I simply add a new file? I know how to add/create a bucket. I can do that easily. But when I try to add a "file" it's not working. I can't figure out what syntax to use or how to get it loaded up..it just does nothing. I have a form where you can upload an image. I am just trying to load the image up to S3. Then later I can get the image from my website and display it...same thing as if I was hosting them on my server but I am wanting them hosted on S3. I have tried the function

$this->s3->putObject($_FILES['photo']['name'], '', 'foldernamehere');
I also tried passing the second parameter as the $_FILES{'photo']['tmp_name'] instead.
I also tried doing file_get_contents on $_FILES['photo']['tmp_name'] and that's not working either. Leaving it blank isn't doing me any good either. Any advice? Thanks.