MySQL Errors

[Daggeth]

I recently moved servers and the new one I am at is having problems with one of my PHP Scripts.

Whenever I try to assign a mysql command, it gives me an error.. so..

$loop = mysql_num_rows($result);

would result in the error

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /path/to/file/here on line 8

however, just using

mysql_num_rows($result);

does not cause any errors..

Can anyone help me out? I am still very new to PHP and MySQL.

[RedDragon]

if you do a num_rows check that $result is a valid query as would be
$result = mysql_query("SELECT * FROM table");