Select menu, Member list med alle dem som ikke er med

Kode 

<?php
$q = mysql_query("SELECT user_id,user_name FROM ".DB_USERS."");
echo "<select name=\"shit-happend\">";
	while($b = mysql_fetch_assoc($q)){
		echo "<option value=\"".$b['user_id']."\">".$b['user_name']."</option>";
	}
echo "</select>";
?>

Kode 

echo "<form method=\"post\" action=\"" . FUSION_SELF . $aidlink . "&page=add\">";
	echo "<select name=\"bruger\">";
		$q = mysql_query("SELECT user_id,user_name FROM ".DB_USERS." WHERE user_id NOT EXIST IN(SELECT bk_id FROM ".DB_BK_MEMBERS.""); 
		while($bruger = mysql_fetch_assoc($q)){
			echo "<option value=\"" . $bruger['user_id'] . "\">" . $bruger['user_name'] . "</option>";
		}
	echo "</select>";
echo "</form>";

Kode 

<?php
echo "<select name=\"bruger\">";
	$q = mysql_query("SELECT user_id,user_name FROM ".DB_USERS." WHERE user_id NOT EXISTS IN(SELECT bk_id FROM ".DB_BK_MEMBERS.""); 
	while($bruger = mysql_fetch_assoc($q)){
		echo "<option value=\"" . $bruger['user_id'] . "\">" . $bruger['user_name'] . "</option>";
	}
echo "</select>";
?>

SQL kode 

 SELECT user_id, user_name, bk_id FROM USERS, DB_MEMBERS WHERE user_id <> bk_id