Likeliness is that you have not signed such a document.
Copyrights are divisible among it's authors.
If you were supplied the text for the pages, the copyright for this text belongs to the one who wrote it, unless ownership has been transfered. If you were supplied photos or illustrations for use in the web site the copyright for each of them belong to their creator unless otherwise assigned. This goes on and on covering every element of the web site. As such, it seems extremely likely that you have contributed some creative aspect of the web site on the whole. You are the sole owner of this contribution unless you ave transfered it to someone else in writing.