Warning: mysql_select_db(): supplied argument is not a valid MySQL-Lin

[Philomena]

i am connected to mysql through my hosting company. I have one page that doesnt have a problem with showing the table info but the this one which has exactly the same code comes up with this error message. Does anyone understand what the problem could be?
thanx
fil

 

[Philomena]

sorry i forgot to leave the error message i keep receiving
Warning: mysql_select_db(): supplied argument is not a valid MySQL-Link resource

fil

 

[Philomena]

I have found the answer to the problem. This piece of code was missing at the very top of the page
<?php require_once('../Connections/connectionfilename.php'); ?>