Description of problem: Currently search results are ordered by increasing topic id number. In future, would like to be able to reorder search results to more easily find topic in search results. So be able to reorder search results by: * topic id (increasing and decreasing topic id numbers) * topic title (both a-z and z-a) Could implement this so that when search results are returned the user clicks on column title to order search results by that topic variable. And click on the same column title to reverse order of search results (so increasing to decreasing topic id numbers, or a-z to z-a topic titles).