Javascript benötige unterstützung

Hallo leute.

ich brauche etwas hilfe bin etwas eingerostet in Javascript... kann mir jemand sagen warum das nicht funktioniert?

Es handelt sich um ein Script:

http://www.jeatrexs.bplaced.net/filemanager/php/gohg/order.php

Wenn man dort z.b. die Anzahl vom Publicserverslots ändert, sollte unten gleich der Preis stehen..

was hab ich falsch gemacht?

Schaut im Sourcecode nach oder hier:

<div align="left">
<form name="best-cs-1" action="order-game-2.php" method="post">
Step 1: Serverinformationen<br />
<br />
<div algin="center">
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="35%">Clanserver</td>
<td width="65%">
<select name="clan" onChange="berechne();">
<option value="0" selected="selected">Kein Clanserver</option>
<option value="2">2 Slots</option>
<option value="4">4 Slots</option>
<option value="6">6 Slots</option>
<option value="8">8 Slots</option>
<option value="10">10 Slots</option>
<option value="12">12 Slots</option>
<option value="14">14 Slots</option>
<option value="16">16 Slots</option>
</select> [Slot 0,70]
</td>
</tr>
</table>
<br />
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="35%">Publicserver</td>
<td width="65%">
<select name="public" onChange="berechne();">
<option value="0" selected="selected" >Kein Publicserver</option>
<option value="2">2 Slots</option>
<option value="4">4 Slots</option>
<option value="6">6 Slots</option>
<option value="8">8 Slots</option>
<option value="10">10 Slots</option>
<option value="12">12 Slots</option>
<option value="14">14 Slots</option>
<option value="16">16 Slots</option>
<option value="18">18 Slots</option>
<option value="20">20 Slots</option>
<option value="22">22 Slots</option>
<option value="24">24 Slots</option>
<option value="26">26 Slots</option>
<option value="28">28 Slots</option>
<option value="30">30 Slots</option>
<option value="32">32 Slots</option>
</select> [Slot 1,40]
</td>
</tr>
</table>
<br />
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="35%">Teamspeak² Server</td>
<td width="65%">
<select name="teamspeak" onChange="berechne();">
<option value="0" selected="selected">Kein Teamspeakserver</option>
<option value="2">2 Slots</option>
<option value="4">4 Slots</option>
<option value="6">6 Slots</option>
<option value="8">8 Slots</option>
<option value="10">10 Slots</option>
<option value="12">12 Slots</option>
<option value="14">14 Slots</option>
<option value="16">16 Slots</option>
<option value="18">18 Slots</option>
<option value="20">20 Slots</option>
<option value="22">22 Slots</option>
<option value="24">24 Slots</option>
<option value="26">26 Slots</option>
<option value="28">28 Slots</option>
<option value="30">30 Slots</option>
<option value="32">32 Slots</option>
<option value="34">34 Slots</option>
<option value="36">36 Slots</option>
<option value="38">38 Slots</option>
<option value="40">40 Slots</option>
<option value="42">42 Slots</option>
<option value="44">44 Slots</option>
<option value="46">46 Slots</option>
<option value="48">48 Slots</option>
<option value="50">50 Slots</option>
<option value="52">52 Slots</option>
<option value="54">54 Slots</option>
<option value="56">56 Slots</option>
<option value="58">58 Slots</option>
<option value="60">60 Slots</option>
<option value="62">62 Slots</option>
<option value="64">64 Slots</option>
<option value="66">66 Slots</option>
<option value="68">68 Slots</option>
<option value="70">70 Slots</option>
<option value="72">72 Slots</option>
<option value="74">74 Slots</option>
<option value="76">76 Slots</option>
<option value="78">78 Slots</option>
<option value="80">80 Slots</option>
<option value="82">82 Slots</option>
<option value="84">84 Slots</option>
<option value="86">86 Slots</option>
<option value="88">88 Slots</option>
<option value="90">90 Slots</option>
<option value="92">92 Slots</option>
<option value="94">94 Slots</option>
<option value="96">96 Slots</option>
<option value="98">98 Slots</option>
<option value="100">100 Slots</option>
</select> [Slot 0,20]
</td>
</tr>
</table>
<br />
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td>Laufzeit</td>
<td width="65%">
<select name="zeit" onChange="berechne();">
<option value="1">1 Monat [10 Euro Setup]</option>
<option value="3">3 Monate[5 Euro Setup]</option>
<option value="6">6 Monate[0 Euro Setup]</option>
<option value="12">1 Jahr[0 Euro Setup]</option>
<option value="24">2 Jahre[0 Euro Setup]</option>
</select>
</td>
</tr>
</table>
<br />
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="35%">Werbung</td>
<td width="65%">
<select name="werbung" onChange="berechne();">
<option value="0" selected="selected">"by GOHG-Server.de" [- 5 Euro]</option>
<option value="1">Ohne</option>
</select>
</td>
</tr>
</table>
<br />
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="100%">
<input name="bestell" type="submit" id="bestell" value="Speichern & Weiter">
<input type="reset" name="resetstep1" value="Zurücksetzen" />
</td>
</tr>
</table>
<br />
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="35%">Entstehende Kosten:</td>
<td width="65%">
<script language="javascript">
function berechne(){
var v_clan = document.getElementsByName("clan").value;
var v_public = document.getElementsByName("public").value;
var v_teamspeak = document.getElementsByName("teamspeak").value;
var v_zeit = document.getElementsByName("zeit").value;
var v_werbung = document.getElementsByName("werbung").value;

var preis = v_clan*0.70+v_public*1.40+v_teamspeak*0.20+v_werbung*5.0;
var zusatz=0.0;

if (v_zeit == 1) zusatz=10.0;
else if (v_zeit == 3) zusatz=5.0;

document.bestell.monatlich.value=preis;
document.bestell.einmalig.value=zusatz;


}

</script>
<input name="monatlich" type="text" size="4" maxlength="5" />
Euro (Monatlich)
<br />
<input name="einmalig" type="text" size="4" maxlength="5" />
Euro (Setupgeb&uuml;hr) </td>
</tr>
</table>
</form>

Freundliche Grüße

document.bestell.monatlich.value=preis;
document.bestell.einmalig.value=zusatz;

...
<script language="javascript" type="text/javascript">  
  ...
  document.getElementById("ergebnis_monatlich").value = preis;  
  document.getElementById("ergebnis_einmalig").value = zusatz;  
</script>
...
<input id="ergebnis_monatlich" name="monatlich" type="text" size="4" maxlength="5"  readonly="readonly" />  
Euro (Monatlich)
<br />
<input id="ergebnis_einmalig" name="einmalig" type="text" size="4" maxlength="5"  readonly="readonly" />  
Euro (Setupgeb&uuml;hr) 
</td>
...