Warning messages

[Guest]

I am recieving the following two warnings on my default.php:

 

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/amazingc/public_html/ecommerce/os/catalog/includes/functions/database.php on line 39

 

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/amazingc/public_html/ecommerce/os/catalog/includes/functions/database.php on line 46

 

 

I have not edited the database.php file at all, i have done some work in the database ( mostly deleting example products and catorgies, etc.).

 

If some could help point me in the right direction on how to get rid of these errors. Thank you very much.