Ho provato ma non viene nulla, la funzione la deve sostituire a quella precendete o devo aggiungerla?

Al momento la mia situazione è questa:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>Verifica Web Marketing</title>
<meta name="keywords" content="Ristorante Firenze, Tagliata Firenze, Carne Firenze, Vino Firenze" />
<meta name="description" content="Clean Type Firenze, il ristorante dove mangiare bene e di qualità! Bere il buon vino toscano! " />
<style>

body{
margin: 0;
padding: 0;
}

#container{
width: 1000px;
margin: 0 auto;
}

#header{
width: 1000px;

}

#main{
width: 1000px;
float: left;
margin: 0 auto;
margin-top: 30px;
}

#cont-main{
width: 800px;
height: 500px;
margin: 0 auto;
}

#cont-text{
width: 400px;
float: right;
margin-top: 50px;
font-size: 18px;
}

#cont-text b{
color: #FF9900;
}

#edit-for{
float: right;
width: 400px;
margin-top: -80px;
}

.part-tex{
margin-left:-200px;
float: left;
}


.apri:hover{ cursorointer;}
.chiudi{ font-size:18px; color:#000; font-weight:bold; position:absolute; right:2%; top:0%; cursorointer;}

.titolo_box{ margin-left:20px;}
#box{ border: 1px solid #000; width:600px; height:600px; background-color:#FFF; display:none; z-index:+300; position:absolute; left:30%; top:20%; -moz-border-radius: 15px; -webkit-border-radius: 15px;
border-radius: 15px;}

#mod-sta{
margin-top: -120px;
margin-left: 20px;
}

#mod-sta ul{
float: left;
margin-left: -45px;
margin-top: -10px;
}

#mod-sta ul li{
list-style: none;
margin-top: 10px;
}

.overlay{
background:#000;
position:fixed;
top:0px;
bottom:0px;
left:0px;
right:0px;
z-index:100;
cursorointer;
/*Trasperenza cross browser*/
opacity: .7; filter: alpha(opacity=70);
-ms-filter:"progidXImageTransform.Microsoft.Alpha(Opacity=70)";

}

#sub-main{
width: 315px;
height: 450px;
float: left;
margin: 0 auto;
}

#delivery{
width: 315px;
height: 450px;
background-color: blue;
text-align: center;
}

#sub-main{
display:none;
}

#delivery table{
margin-top: -90px;
}

.same{
margin-top: 100px;
}

</style>

<script type="text/javascript">

function UpdateCost(prezzo) {
var sum = 0.50;

sum = Number(prezzo);

document.getElementById('totalcost').value = sum.toFixed(2);
}

</script>

<script type="text/javascript">



</script>

<script src="js/jquery.js" type="text/javascript"></script>

<script>

$(document).ready(function() {
$(".same").click(function(){
$("#sub-main").slideToggle("slow");
});
});

</script>

</head>
<body>

<div id="container">

<div id="header">
<img src="images/banner.jpg"/>
</div>

<div id="main">

<div id="cont-main">
<img src="images/product01.jpg"/>

<div id="cont-text">
<b>Penna gel Niceday</b>
<p>Penna gel Niceday grip tratto medio colore rosso, conf. da 12 pz
Codice Articolo QM1-1621903
</p>

<p style="font-weight:bold;font-size:20px;color:#f00;">A partire da
€ 0,50 / penna
</p>
</div>

<form id="edit-for" name="form1" action="acquista.html" method="post" >
<h3>Aggiungi opzione</h3>
<table border="0" cellspacing="2" cellpadding="2">

<tr>

<td>

Quantita' <input name="primo" type="textbox" onKeyUp="HandleKey()" value="0"><br />
</td>
</tr>

<tr><td>&nbsp;</tr></tr>

<tr>
<td><input name="secondo" type="radio" onclick="UpdateCost(this.value)" value="1" /></td>
<td class="part-tex">Senza stampa</td>
<td></td>
</tr>



<tr>
<td><input name="secondo" type="radio" onclick="UpdateCost(this.value)" value="2" /></td>
<td class="part-tex"><p class="apri"><div id="sub-main">
<div class="evento">
<table>

<tr>
<td><h3>Colore</h3></td>
</tr>

<tr>
<td>
<select name="nome">
<option value="nero">Nero</option>
<option value="rosso">Rosso</option>
<option value="bianco">Bianco</option>
</select>
</td>
</tr>

<tr>

<td><h3>Tipologia di stampa</h3></td>
</tr>

<td>
<ul>
<li><input type="radio" onClick="HandleKey()" value="3" name="terzo"checked>Serigrafia</li>
<li><input type="radio" onClick="HandleKey()" value="4" name="terzo">Incisione</td></li>
</ul>
</td>
<br/>
<br/>
<tr>

<td><h3>Tipo di font</h3></td>
</tr>

<tr>
<td>

<select name="nome">
<option value="nero">Arial</option>
<option value="rosso">Vardana</option>
<option value="bianco">Times New Roman</option>
</select>

</td>

</tr>

<br/>
<br/>

<tr><td><h3>Scrivi il testo che desideri stampare</h3></td></tr>
<tr>
<td><textarea name="nome_testo" cols="22" rows="5" style="width:300px;height:50px;"></textarea></td>
</tr>

<tr>
<td>&nbsp;</td>
</tr>

</table>

</div>
</div><input type="button" value="Con stampa" name="nome" class="same"></p></td>
</tr>



<tr>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>

<tr>
<td>totale offerta iva inclusa €: <input name="somma" type="textbox" value="0"></td>
</tr>

<tr>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>

<tr>
<td><input type="submit" value="Aggiungi al Carrello"></td>
<td></td>
</tr>

</table>

</form>






</div>

</div>



</div>

</div>

</body>

</html>

Grazie.