Problems with FORM

[wxdqz]

This is my Code:

So I want to reload the page and give the page the variable f_sparte .... so that I can user the VAR.
I think I have to do it with javascript ... so I tested onchange="" but I don't know how to reload the frame and set the variable to the selected value...

<select name="f_sparte" class="text">
<option value=http://www.webdeveloper.com/forum/archive/index.php/"0">Bitte w&auml;hlen Sie eine vorhandene Kategorie aus</option>
<?php
$abfrage_kategorien = mysql_query("select * from sparten ORDER BY sparten ASC");
$anzahl_kategorien = mysql_num_rows($abfrage_kategorien);
for($i=1;$i<=$anzahl_kategorien;$i++){
$array_kategorien = mysql_fetch_array($abfrage_kategorien);
?>
<option <?php if($array_kategorien[0] == $f_sparte) print "selected"; ?> value="<?php print $array_kategorie[0]; ?>">
<?php
print $array_kategorien[0];
?>
</option>
<?php
}
?>

Thx a lot in advance ... and sorry fpr bad english