undefined index mean the variable you are referencing dos not exist.
the error means that there is no URL variable named Author, or FileName for the recordset to use.
when using URL variables in your recordset, you should use iisset() to check if the variable exists:
38. $rsSearch->bindParam("text", "".(isset($_GET['Author'])?$_GET['Author']:"") ."", "-1xyz"); //varAuthor
39. $rsSearch->bindParam("text", "".(isset($_GET['FileName'])?$_GET['FileName']:"") ."", "-1xyz"); //varFileName