[Plugin: Custom Query Fields] Search results

Hi, I registered the function and used the following url my_site.com/?price=142 but nothing found. I guess WordPress used index.php template to display the results. So what’s wrong? What template should I use to display such search results?

http://wordpress.org/extend/plugins/custom-query-fields/