PHP Searching Mulitple Tables

[Inque187]

I am trying to search two tables with the same structure in a PHP search form. I am stuck on trying to get it to search both tables. I am relatively new to PHP/MySQL and i have bee thru the MySQL website and came up with this:

$result = mysql_query(" 
	SELECT bans1.nick1, bans2.nick2
	FROM pb_bans_04 as bans1
	LEFT JOIN pb_bans05 as bans2 ON bans1.nick1 = bans2.nick2
	WHERE nick LIKE '%$search1%' 
");  

$rows = mysql_num_rows($result);

Ever time I run the search, I get errors

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource

What am I doing wrong?

[siwis]

You need to specify which table 'nick' is from