When using the code below, the file attached does not get renamed to the original, user entered file name. This is inside a simple mail contact form on an Opencart store. Does anyone have any idea why this code isn't acknowledging the second parameter?

Code:
if (file_exists($_FILES['file']['tmp_name'])) {
				$mail->addAttachment($_FILES['file']['tmp_name'], $_FILES['file']['name']); 
			}