Page editor

I thought I saw this but:

Is there a way to change the editor used for editing pages in the admin panel? Whenever I want to use code using the Source view, I save it and it’s all fine, but when I go back to edit it the editor converts it all into html (“?>” and the like) and it’s reaaally annoying.

Thanks

If you can help me find a solution, the editor is “ckeditor”, it might be a setting or something