My urls are entered through a set of checkboxes on the search form. When the results template is displayed, those urls get displayed. How can I avoid that?

This can be nicely solved by a piece of JavaScript code, courtesy of gpa.unep.org where you can see it running. Try searching test url:tu-nt.ucis.dal.ca and look at the template page source at http://www.gpa.unep.org/search_forms/gpa.html .