Im getting this error...

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in e:\domains\m\meltdownsoftware.co.uk\user\htdocs\redirect.php on line 20

Here is the line it is occuring on...

PHP Code:
$rows=mysql_num_rows($redirect); 
I have no idea why it is not working, any ideas?

ILMV