Remember dropdown item OR select if GET - php

Question

I currently have this code to remember the last selected item on post.
<select tabindex="1" name="system_customer">
<option value="Choose">- Choose a Customer -</option>
<?PHP while ($row = mysql_fetch_array($result_get_users))
{
echo "<option value='".$row['id']."'";
echo $system_customer == $row['id'] ? 'selected="selected"' : '';
echo ">".$row['firstname']." ".$row['lastname']."</option>";
} ?>>
</select>
On load (before submitting) the list defaults to "Choose". What I would like to do, is if the URL has "userid=1" to select user 1, or if it is "userid=2" then select user 2, but keep the code to remember the last selected.
Thank you.
PS - cannot use mysqli or PDO due to the software I am writing a module for. It is hard coded and encrypted.

Answer 1

Add this above your code -
$system_customer = "";
if (!empty($_GET['userid'])) {
$system_customer = $_GET['userid'];
}
Then -
<select tabindex="1" name="system_customer">
<option value="Choose">- Choose a Customer -</option>
<?PHP
while ($row = mysql_fetch_array($result_get_users)) {
echo "<option value='".$row['id']."'";
echo $system_customer == $row['id'] ? 'selected' : '';
echo ">".$row['firstname']." ".$row['lastname']."</option>";
}
?>
</select>

Answer 2

You can use session or cookie
for exp :
<?PHP
Session_start();
if ( isset ( $_POST['system_customer'] ) ) {
$_SESSION['SELECTED_USER_ID'] = $_POST['system_customer'];
?>
and you haave to make some changes in you dropdown list
<select tabindex="1" name="system_customer">
<option value="Choose">- Choose a Customer -</option>
<?PHP while ($row = mysql_fetch_array($result_get_users)) {
echo "<option value='".$row['id']."'";
echo $_SESSION['SELECTED_USER_ID'] == $row['id'] ? 'selected="selected"' : '';
echo ">".$row['firstname']." ".$row['lastname']."</option>";
}
?>>
</select>
in you select form you have to check if session id is equal to row if then put selected attribiut for that option .
but if you want to save details for long time it's better to use cookie or databases you can't do it in another cases .