Problema select

[dailybreaker]

Am un formular cu un text box (Username) si un select (selecteaza anul).
Daca utilizatorul completeaza campul USERNAME dar nu selecteaza ANUL, in momentul cand apasa Submit valoarea introdusa in campul USERNAME se pastreaza.
Cum pot face ca daca utilizatorul selecteaza ANUL dar nu completeaza campul USERNAME, dupa ce apasa butonul Submit ANUL selectat sa se pastreze si sa nu revina la valoarea initiala (YEAR)?

<?php
if($_POST)
{

$username = $_POST['username'];
$year = $_POST['year'];
if (eregi('^[A-Za-z0-9_]{4,12}$',$username))
{
$valid_username=$username; }
else
{
$error_username='Introduceti user'; }


if ($year==0)
{
$error_year='Introduceti an'; }
else
{
$valid_year=$year; }

if( (strlen($valid_username)>0) && $valid_year>0 )
{
header("Location: ok.html");
}
}
?>

<form method="post" action="" name="form">

<label > Username</label>
<div>
<input id="username" name="username" value="<?php echo $valid_username; ?>"maxlength="255" tabindex="3" />

<label>Anul:</label>
<select name="year">
<option value="0">Year</option>
<option value="2000">2000</option>
<option value="1998">1998</option>
<option value="1997">1997</option>
</select>

<input type="submit" value="Submit" >
</form>

[Birkoff]

[dailybreaker]

[Birkoff]

solutia ta e ok, ce iti dadusem eu era ca sa poti genera orice select cu valorile dintr-un array (care array poate fi rezultatul din bd de exemplu)

[dailybreaker]

[starlays]