There is normally one strtolower present but it is only applied to the session variable that is being compared, not to the posted element from the form. This is why the entry with the lowercase works but not with the uppercase. You will need to wrap the strtolower around the input value. If you post back with your page that has the form on it or just the Validation code from the top of the page I can show you where this would need to be inserted.