Drop down menu in ****_list.php

Hi,

can you help me on this one ?

I have found this code in the forum :
global $conn;

$links = "<select onchange=\"window.location.href=this.options[this.selectedIndex].value;\">";

$str = "select Modele from _modele";

$rs = db_query($str,$conn);

while ($data = db_fetch_array($rs))

$links.="<option value=\"_modele_list.php?a=search&value=1&SearchFor=".$data["Modele"]."&SearchOption=Contains&SearchField=Modele\">".$data["Modele"]."</option>";

$links.="<select>";

echo $links;
so I put it on the _lisp.php page to make it look like the picture below :

but when I select an item from this menu I got this error :

any help will be very welcome :-)

thank you

jb