How to filter data from a MySQL Database Table with PHP

I'm attempting to code a search box that will browse a database column. The record will be printed in the table below if the search returns results matching the column.

I'm conducting a search on a column that lists a firm record's county. Although no errors are shown, the table is empty when I search for a county that is in the database. Since I believe the code should function, I am unable to see what I did incorrectly. I would appreciate any assistance.

DBconnect.php

<?php
// connect to the database
$db = 'stylecraft_dev';
$host = 'localhost';
$user = 'stylecraft_admin';
$password = '000000';

$dbConn = mysql_connect($host,$user,$password) or die("Failed to connect to database");
$result = mysql_select_db($db, $dbConn) or die("Failure selecting database");
?>

form.php

        <?php
            $sql = "SELECT * FROM member ";

            if (isset($_POST['search'])) {

                $search_term = mysql_real_escape_string($_POST['search-box']);

                $sql .= "WHERE MB_COUNTY = '{$search_term}' ";
            }

            $query = mysql_query($sql) or die(mysql_error());
            ?>

            <form name="search_form" method="POST" action="stockists.php">
            Search: <input type="text" name="search_box" value=" "/>
            <input type="submit" name="search" value="Search the stockists...">
            </form>

            <table width="70%" cellpadding="5" cellspace="5">

            <tr>
                <td><strong>Company Name</strong></td>
                <td><strong>Website</strong></td>
                <td><strong>Phone</strong></td>
                <td><strong>Address</strong></td>
            </tr>

            <?php while ($row = mysql_fetch_array($query)) {?>
            <tr>
                <td><?php echo $row['MB_COMPANY'];?></td>
                <td><?php echo $row['MB_MOBILE'];?></td>
                <td><?php echo $row['MB_PHONE'];?></td>
                <td><?php echo $row['MB_COUNTY'];?></td>
            </tr>

            <?php } ?>
            </table>