At this point, only selective Web page's HTML files are transferred. The analyzer builds a directed graph based on transferred HTML file. This graph explains structure of connected pages and connected sections inside one domain. Figure 2 shows one example. Then each page and section are scanned with breadth first search and are judged whether they are want ads.
Judgment is done by including keywords.
If it is a desired page or section, it is appended to the database. Appended data include URL and names of companies. The structure of this database is shown by Figure 3 . Even if this analyzer judges former category of employment, we allow it. Because it is still want ads.