Browser Lock is a user-defined, client-side portal, which resides on the user's machine, and can restrict Web access to only those sites which are listed. The user has complete control over which Web sites the portal offers links to. Users can update these sites by adding or deleting web-site addresses on the Browser Lock access list, and their 'Personal Portal Page' is updated automatically. Browser Lock is a combination 'personal' Internet portal and a Web access filter. A portal is an Internet gateway - the first site, or the 'launch pad', which users make their initial point of access to the Internet. A portal is usually a simple page, held on a remote Web server, that has links to other areas on the Internet. 48% of web advertising revenue is generated by sellers promoting their products and services oncomes ready supplied with the addresses of 5,000 sites which have already been catalogued by subject area. This list is by no means definitive - it is a guide for users. Browser Lock's graphic interface is