[Zope] 3RD REQUEST: PLEASE HELP

[Ben Ocean]

Hi;
I have a form in which I create a variable like this:

<dtml-call "REQUEST.set('shipping',_.int(subtotal)*.05)">
<input type=hidden name=shipping value=<dtml-var shipping>>

which is successfully used in said form like this:

  <dtml-if shipping>
   <tr>
    <td><font style="font: <dtml-var "sizeCalc(15,size(_.None,_))">px 
verdana">Shipping:</font></td>
    <td><font style="font: <dtml-var "sizeCalc(15,size(_.None,_))">px 
verdana"><dtml-var shipping fmt=dollars-and-cents></font></td>
   </tr>
  </dtml-if>

but when I try to render it in the form to which I pass it like this:

  <dtml-if shipping>
    <tr>
     <td><font style="font: <dtml-var "sizeCalc(15,size(_.None,_))">px 
verdana">Shipping</font></td>
     <td>&nbsp;</td>
     <td>&nbsp;</td>
     <td><font style="font: <dtml-var "sizeCalc(15,size(_.None,_))">px 
verdana"><dtml-var shipping fmt=dollars-and-cents></font></td>
    </tr>
  </dtml-if>

it doesn't render at all! So I try something sneaky like this:

  <dtml-if shipping>
  <dtml-let shippingit="shipping+0.00">
    <tr>
     <td><font style="font: <dtml-var "sizeCalc(15,size(_.None,_))">px 
verdana">Shipping</font></td>
     <td>&nbsp;</td>
     <td>&nbsp;</td>
     <td><font style="font: <dtml-var "sizeCalc(15,size(_.None,_))">px 
verdana"><dtml-var shippingit fmt=dollars-and-cents></font></td>
    </tr>
  </dtml-let>
  </dtml-if>

and I get this error:

Error Type: ValueError
Error Value: invalid literal for int(): 126.0

I'd just like the stupid thing to show up in dollars-and-cents. Any ideas?
TIA,
BenO