Aide sur un code

Bonjour,
j essaye d intégrer a mon blog ce code
il s affiche bien ,mais ne calcul rien
pourtant la bas il fonctionne

http://www.espacejavascript.com/

<table><tr><td>
<form method="POST" name="selectionForm">
<b>PPizza</b><br>
Petite €10.00
<input type="checkbox" name="Steak" value="10.00" onclick="this.form.total.value=calculateTotal(this);">
Normal €12.00
<input type="checkbox" name="Chicken" value="12.00" onclick="this.form.total.value=calculateTotal(this);">
Large €15.00
<input type="checkbox" name="Sushi" value="15.00" onclick="this.form.total.value=calculateTotal(this);">
<br><br>
<b>Supplément :</b> <br>
<input type="radio" name="Sauce" value="0.00" onclick="this.form.total.value=calculateTotal(this);"> Rien
<br>
<input name="Sauce" type="radio" value="1.00" onclick="this.form.total.value=calculateTotal(this);"> + de fromage €1.00
<br>
<input type="radio" name="Sauce" value="2.00" onclick="this.form.total.value=calculateTotal(this);"> végétarien €2.00
<br>
<input type="radio" name="Sauce" value="3.00" onclick="this.form.total.value=calculateTotal(this);"> jambon €3.00
<br>
<br>
<input type="hidden" name="calculatedTotal" value="0">
<input type="hidden" name="previouslySelectedRadioButton" value="0">
<strong>Your total is:</strong>
<input type="text" name="total" readonly onfocus="this.blur();">
</form>
</td></tr></table>
<p><font face="verdana" size="1">Powered and Generated by </font><a href="http://www.espacejavascript.com" target="_blank"><font face="verdana,arial,helvetica" size="1" color="black">http://www.<b>espacejavascript</b>.com</font></a></p>

merci de vos reponse et de l aide