In order to browse a web site by using a browser program running on a computer, a web browser obtains, from a server holding information concerning web sites, the page structure and the attributes for the web pages at the site, and displays them in correlation with each other. Further, the web browser can enable the altering by a user of the display of the page structure and the page attributes, so that in response to user manipulations, the page structure and page attribute display can be dynamically changed. In order to facilitate such an alteration by a user, a GUI (Graphical User Interface) command is provided for changing the page structure and page attribute display.