Wikipedia: In all countries that are members of the Berne Convention, copyright is automatic and need not be obtained through official registration with any government office. Once an idea has been reduced to tangible form, for example by securing it in a fixed medium (such as a drawing, sheet music, photograph, a videotape, or a computer file), the copyright holder is entitled to enforce his or her exclusive rights. However, while registration isn't needed to exercise copyright, in jurisdictions where the laws provide for registration, it serves as prima facie evidence of a valid copyright. The original copyright owner of the copyright may be the employer of the author rather than the author himself, if the work is a "work for hire".
Basically, a copyright line somewhere is enough in most cases.