Quick fix to PHP/MySQL search

Hi, Need a simple fix on an existing website that utilises a MySQL database and PHP search. Search works initially, but pagination has stopped working and also when returning to search results after viewing a specific result the results disappear. You can see the site at [login to view URL] - THIS IS A CLIENT SITE, UNDER NO CIRCUMSTANCES CONTACT THEM DIRECTLY. You must only bid if you can start this project immediately and complete within a few hours. Should be a very simple fix. You must also be able to tell us exactly what the issue was and how it was rectified. Thanks.