Searching for all posts

On a site that is running wordpress I have a search box that searches for keyword, location and category. The location is a post meta field. When i search for all jobs for a location (by using all as the keyword), i get a certain number of results, but if i take all out of the keywords it shows more results. Is it possible to show all results when using the keyword all in the search chriteria? If not how do i get it to not sue the all keyword if all has been submitted?