The present invention improves application of a style to a view object when a document for a Web page to be edited is edited on a browser-type edit screen. First, a view object is detected from a managed document. Then, a direct style directly described in the managed document and an indirect style identified only by referring to an external document are collected. A browser-type edit screen is generated in which the direct and indirect styles are applied to each view object. The content of the managed document is synchronized with the edited content on the browser-type edit screen based on the editing operations on the browser-type edit screen.