Eccoti il codice corretto:

codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<link href="file/style.css" rel="stylesheet" type="text/css" />
</head>

<SCRIPT type="text/javascript">
function verifForm(formulaire)
{
if(formulaire.Nome.value == "")
{
alert('You forgot to enter your name!');
return false;
}
else
return true;
}
</SCRIPT>

<body>
<table width="961" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td> </td>
</tr>
</table>



<table width="961" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td height="15" class="tabellaTop"></td>
</tr>
<tr>
<td bgcolor="#d9d9d9"><table width="90%" border="0" align="center" cellpadding="0" cellspacing="10">
<tr>
<td width="380" class="tahoma14"><form action="formcdosys.asp" method="post" name="form1" id="form1" onsubmit="return verifForm(this);">
<fieldset>
<legend class="tahoma_Arancio14">Per Contattarci</legend>
<div class="fieldbox">
<label for="theName">Nome:<span>*</span>

<input name="Nome" type="text" size="44" id="theName" />
</label>
<p class="field_desc">Inserisci il tuo nome e cognome.</p>
</div>
<div class="fieldbox">
<label for="theURL">Società: *

<input name="Società" type="text" value="nome della società" size="44" id="theURL" />
</label>
<p class="field_desc">Inserisci la tua società.</p>
</div>
<div class="fieldbox">
<label for="theURL">Indirizzo:<span>*</span> 

<input name="Indirizzo" type="text" value="il tuo indirizzo" size="44" id="theURL" />
</label>
<p class="field_desc">Inserisci il tuo indirizzo postale.</p>
</div>
<div class="fieldbox">
<label for="theURL">Recapito telefonico:<span>*</span> 

<input name="recapito_telefonico" type="text" value="n." size="44" id="theURL" />
</label>
<p class="field_desc">Inserisci il tuo numero di telefono.</p>
</div>
<div class="fieldbox">
<label for="theURL">Sito Internet: 

<input name="sito" type="text" value="www" size="44" id="theURL" />
</label>
<p class="field_desc">Hai un sito web? Inseriscilo.</p>
</div>
<div class="fieldbox">
<label for="email">Email:<span>*</span>

<input name="email" type="text" value="la tua email" size="44" id="email" />
</label>
<p class="field_desc">Promettiamo di non condividere il tuo indirizzo email con NESSUNO.</p>
</div>
<div class="fieldbox">
<label for="message">Messaggio:<span>*</span>

<textarea name="messaggio" cols="38" rows="6" id="message"></textarea>
</label>
<p class="field_desc">Scrivi il tuo commento qui ... questa finestra si espanderà automaticamente! 



</p>
</div>


 </p>


 </p>


<span>*</span> - indica i campi obbligatori </p>
</fieldset>
<input class="buttons" type="submit" value="Invia"/>
</form></td>
</tr>
</table></td>
</tr>
<tr>
<td height="15" class="tabellaDown"> </td>
</tr>
</table>
</body>
</html>
PS: comunica a LeleFT dove spostare la discussione e ricordati 'sti benedetti tag !