Link two dynamic drop down menus php mysql

Link two dynamic drop down menus php mysql

I have two drop down menus that are populated from the same table. What I
would like to do is make them automatically match selected values with
each other. In other words, if client 2a is chosen I want account 2a to be
automatically selected in the other drop down menu and vice versa. It
seems like it should be easy to do without jquery because they have
matching ids, but I can't seem to make it happen.
Here is the code:
<p>Client's full name: <select name="client"><option value="<? echo $c_id
?>" ><? echo $client ?></option>
<?php //retrieve all the clients and add to the pull-down menu
$q = "SELECT c_id, CONCAT_WS(' ', c_firstName, c_middleName,
c_lastName)FROM client ORDER BY c_lastName, c_firstName ASC";
$r = mysqli_query ($dbc, $q);
if (mysqli_num_rows($r)> 0) {
while ($row = mysqli_fetch_array ($r, MYSQLI_NUM)) {
echo "<option value=\"$row[0]\"";
//Check for stickyness
if (isset($_POST['client'])&&($_POST['client']== $row[0]))
echo ' selected="selected"';
echo ">$row[1]</option>\n";
}
}
?>
</select></p>
<p>Account nickname: <select name="nickname"><option value="<? echo $c_id
?>" ><? echo $nickname ?></option>
<?php //retrieve all the Acct Nicknames and add to the pull-down menu
$q = "SELECT c_id, c_nn FROM client ORDER BY c_nn ASC";
$r = mysqli_query ($dbc, $q);
if (mysqli_num_rows($r)> 0) {
while ($row = mysqli_fetch_array ($r, MYSQLI_NUM)) {
echo "<option value=\"$row[0]\"";
//Check for stickyness
if (isset($_POST['nickname'])&&($_POST['nickname']== $row[0]))
echo ' selected="selected"';
echo ">$row[1]</option>\n";
}
}
?>
</select></p>
</div>