MySQL Forums :: Newbie :: Error: mysql_select_db() expects parameter 2 to be resource, null given

I'm gettting the error Warning: mysql_select_db() expects parameter 2 to be resource, null given in C:\xampp\htdocs\SwenkePTO\indextest3.php on line 98 and 100 using the following code. I'm new to MySQL, so any help with understanding what it means is greatly appreciated. It did work without this error on my desktop, but not my laptop...

Thanks

98 mysql_select_db($database_SwenkePTO_db, $SwenkePTO_db);
99 $query_Swenke_PTO_Chair_results = "SELECT * FROM chairform_results";
100 $Swenke_PTO_Chair_results = mysql_query($query_Swenke_PTO_Chair_results, $SwenkePTO_db) or die(mysql_error());
101 $row_Swenke_PTO_Chair_results = mysql_fetch_assoc($Swenke_PTO_Chair_results);
102 $totalRows_Swenke_PTO_Chair_results = mysql_num_rows($Swenke_PTO_Chair_results);