This might help.
From Wikipedia <
http://en.wikipedia.org/wiki/Regiment>
A regiment is a military unit, consisting of a variable number of battalions - - commanded by a colonel. Depending on the country of origin and mission, a modern regiment may be similar to a brigade, in that both range in size from a few hundred to 2,000-3,000 soldiers, depending on the branch of service and method of organization.
From Wikipedia <
http://en.wikipedia.org/wiki/Battalion>
A battalion is a military unit usually consisting of between two and six companies and typically commanded by a Lieutenant Colonel. Several battalions are grouped to form a regiment.