<?php
if(isset($_POST['look']))      $look=$_POST['look'];
else      $look="";
?>
    Your field was :
    <b><?php echo $_POST['look'];  ?> </b>
    <br/><br/>
<?php

$db = mysql_connect('localhost', 'xxxxxx', 'xxxxxxx')  or die('Connection error '.mysql_error());

mysql_select_db('aftersun_cartouches',$db);

$result = mysql_query('SELECT * FROM catouches WHERE "Modeles" LIKE '%$look%'');

while ($data = mysql_fetch_array($result))
{
echo $data['No_Cartouches'];
}

mysql_free_result($query);
mysql_close();
?>

<form method="POST">
    <input name="look" type="text"/>
    <input name="valider" type="submit" value="OK"/>
</form>