Refresh Javascript Variable without page reload

Question

I have this form with a select list box in it. It shows a total that will change when the user selects different options:

<form action="https://www.paypal.com/cgi-bin/webscr" method="post" name="paypal">
                                               <input type="hidden" name="cmd" value="_cart">
                                               <input type="hidden" name="upload" value="1">
                                               <input type="hidden" name="currency_code" value="GBP">
                                               <input type="hidden" name="business" value="contact@contact.org">   
                                            <select name="handling_cart" onChange="refresh();" style="margin-bottom: 5px;">
                                            <option selected value="10.00">UK £10.00</option>
                                            <option value="30.00">France £30.00</option>
                                            <option value="35.00">Germany £35.00</option>
                                            </select>                               
                                            </td>
                                        </tr>
                                        <tr>
                                        <td>Grand Total:</td>
                                        <td>£
                                        <script lanuage="JavaScript">                                           


                                        var delivery = document.paypal.handling_cart.value;

                                        var total = parseInt(jtotal)+parseInt(delivery); 
                                        document.write(total);
                                        </script></td>
                                        </tr> 

I haven't got a function refresh() but I'm guessing I'm going to need one?

TIA

Answer 1

Okay, created refresh() for you. Working demo is here http://jsfiddle.net/hwwDj/3/

<form action="https://www.paypal.com/cgi-bin/webscr" method="post" name="paypal">
                                               <input type="hidden" name="cmd" value="_cart">
                                               <input type="hidden" name="upload" value="1">
                                               <input type="hidden" name="currency_code" value="GBP">
                                               <input type="hidden" name="business" value="contact@contact.org">   
                                            <select name="handling_cart" onChange="refresh();" style="margin-bottom: 5px;">
                                            <option selected value="10.00">UK £10.00</option>
                                            <option value="30.00">France £30.00</option>
                                            <option value="35.00">Germany £35.00</option>
                                            </select>                               
                                            </td>
                                        </tr>
                                        <tr>
                                        <td>Grand Total:</td>
                                            <td><div id="etd">£</div></td>
                                            </tr> 
                                        <script lanuage="javascript">                                           
var jtotal=10;

                                        var delivery = document.paypal.handling_cart.value;
                                            function refresh()
                                            {
                                                  delivery = document.paypal.handling_cart.value;
                                        var total = parseInt(jtotal)+parseInt(delivery); 
   document.getElementById("etd").innerHTML="£ "+total;
                                            }


                                            //document.write(total);
                                        </script>