IMDB keeps auto correcting new name. -

There is nothing wrong. "Lastname, Firstname" - in your case, "Parkhill, J." - is the correct format for storage in the server. Don't worry. Although it will appear as "Parkhill, J." on a submission page, it will display everywhere as "J. Parkhill".

That said, if you really, really want your name to be stored in the format "J. Parkhill", you can contact the Help Desk and ask a manager to override the server and manually correct it. (This option is available and generally used to store the names of groups and bands that have multiple words in their names, so that, for example, Led Zeppelin is stored as "Led Zeppelin" and not "Zeppelin, Led". It's not consistently used throughout the IMDb.)

By the way, when you submit the correction, don't forget to make sure the "Preserve previous name on existing credits" box underneath the correction field is checked.