The rapid growth of the Internet makes information available anywhere and anytime. Most businesses run Web-based front-end databases upon which online services are offered to end-users. The next generation of the Web, the semantic Web, seeks to offer data in a usable form for automatic reasoning. To this purpose, it is necessary to make existing database content ready-to-use for semantic Web applications, which use ontologies to formally define the semantics of their data. As a result, a large number of initiatives focus on building ontologies through automatic or semi-automatic processes. In this paper we present a semi-automatic reverse engineering approach that uses a relational database's HTML forms and a set of transformation rules to produce to an OWL ontology.