At present, most of web-based applications are on the basis of HTML-based form documents. These HTML-based form documents only play a role as user interfaces, but they don"t involve the procedures or rules of processing business works that aim to documents. However, form documents imply methods for treating documents, and these procedural knowledge embedded can utilize to actively perform business work processes. Procedural knowledge is defined in ERML(Executable Rule Markup Language), which is a XML-based rule markup language that has a format of Prolog rules. The ERML is not only executable in an inference engine, but also can be geared with WfMS (Workflow Management System) and can be used in a heterogeneous rule-based application. Thus, this paper proposes a ERML-based scheme for processing active documents as device for automating a workflow that involve a process of treating documents. Our active documents themselves involve declarative knowledge to support the process and control of business rules embedded in documents and the automation of processing documents. Also, we propose a framework for processing the defined active documents. In order to demonstrate the usefulness of the proposed framework, a prototype called ActiveWebForm is designed and implemented for a case of processing a request for requisition of IP(Internet Procurement) system. As a result, our approach is expected to contribute to intelligence and automation of Internet applications as processing documents by embedding declarative knowledge.