Error Messages Explained

Since PHP 4.2.0, PHP returns an appropriate error code along with the file array. The error code can be found in the ['error'] segment of the file array that is created during the file upload by PHP. In other words, the error might be found in $_FILES['userfile']['error'].

UPLOAD_ERR_OK: Value: 0; There is no error, the file uploaded with success.
UPLOAD_ERR_INI_SIZE: Value: 1; The uploaded file exceeds the upload_max_filesize directive in php.ini.
UPLOAD_ERR_FORM_SIZE: Value: 2; The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.
UPLOAD_ERR_PARTIAL: Value: 3; The uploaded file was only partially uploaded.
UPLOAD_ERR_NO_FILE: Value: 4; No file was uploaded.

Note: These became PHP constants in PHP 4.3.0.