function packageSelected()
{

 var theForm = getElement("conference_delegate_form_2009");
 var delegate_package = getRadioButtonValue(theForm.dp_delegate_package);
 var organisation = getRadioButtonValue(theForm.dp_organisation_type);

 var amount = calculateInvoiceAmount(delegate_package, organisation);
 setInvoiceAmount(amount);
}


function calculateInvoiceAmount(delegate_package, organisation)
{
 var amount = "";

 if (organisation == "dp_public_sector" || 
     organisation == "dp_exhibitor" )
 {
   switch (delegate_package)
   {
    case("dp_delegate_package_A"): amount = "309";
                                   break;    

    case("dp_delegate_package_B"): amount = "229";
                                   break;

    case("dp_delegate_package_C"): amount = "169";
                                   break;
                                   
    case("dp_day_one_only"): amount = "99";
                                   break;
                                   
    case("dp_day_two_only"): amount = "69";
                                   break;
   }
 }
 else if (organisation == "dp_private_sector")
 {
   switch (delegate_package)
   {
    case("dp_delegate_package_A"): amount = "409";
                                   break;    

    case("dp_delegate_package_B"): amount = "339";
                                   break;

    case("dp_delegate_package_C"): amount = "279";
                                   break;   
                                   
    case("dp_day_one_only"): amount = "199";
                                   break;
                                   
    case("dp_day_two_only"): amount = "169";
                                   break;
   }
 }

 return amount;
}

function setInvoiceAmount(amount)
{
 var invoice_amount = getElement('inv_amount');

 if (invoice_amount)
 {
   invoice_amount.value = String.fromCharCode(163) + amount;  
 }
}

function getElement(elementId)
{
 var element = null;

 if (document.all)
 {
  element = document.all[elementId];
 }
 else if (document.getElementById)
 {
  element = document.getElementById(elementId);
 }

 return element;
}