How do I un-select a drop-down selection when a checkbox is un-checked?

[Taylor Smith]

I have a checkbox that when selected it fills in the shipping address(to match the billing address. When un-checked it should clear all the fields in the shipping address section of the form. It works up until the drop downs. I have tried multiple ways of formatting it but i can't seem to get it to clear once the checkbox is un-checked. Any assistance would be great.

<script>
var shipName = "";
var shipStreet = "";
var shipStreet2 = "";
var shipCity = "";
var shipcountrySelect = 0;
var shipProvState = 0;
var shipPostalZip = "";
var shipDayPhone1 = "";
var shipDayPhone2 = "";
var shipDayPhone3 = "";
var shipCellPhone1 = "";
var shipCellPhone2 = "";
var shipCellPhone3 = "";
var shipEmail = "";
 
function FillFields(box) {
 if(document.bookform.box.checked) {
document.bookform.shipName.value = document.bookform.billName.value;
document.bookform.shipStreet.value = document.bookform.billStreet.value;
document.bookform.shipStreet2.value = document.bookform.billStreet2.value;
document.bookform.shipCity.value = document.bookform.billCity.value;
document.bookform.shipCountrySelect.selectedIndex = document.bookform.billCountrySelect.selectedIndex;
document.bookform.shipProvState.selectedIndex = document.bookform.billProvState.selectedIndex;
document.bookform.shipPostalZip.value = document.bookform.billPostalZip.value;
document.bookform.shipDayPhone1.value = document.bookform.billDayPhone1.value;
document.bookform.shipDayPhone2.value = document.bookform.billDayPhone2.value;
document.bookform.shipDayPhone3.value = document.bookform.billDayPhone3.value;
document.bookform.shipCellPhone1.value = document.bookform.billCellPhone1.value;
document.bookform.shipCellPhone2.value = document.bookform.billCellPhone2.value;
document.bookform.shipCellPhone3.value = document.bookform.billCellPhone3.value;
document.bookform.shipEmail.value = document.bookform.billEmail.value;
}
else {
document.bookform.shipName.value = shipName;
document.bookform.shipStreet.value = shipStreet;
document.bookform.shipStreet2.value = shipStreet2;
document.bookform.shipCity.value = shipCity;
document.bookform.shipcountrySelect.value = shipcountrySelect.options[0].selected = true;
document.bookform.shipProvState.value = shipProvState.options[0].selected = true;
document.bookform.shipPostalZip.value = shipPostalZip;
document.bookform.shipDayPhone1.value = shipDayPhone1;
document.bookform.shipDayPhone2.value = shipDayPhone2;
document.bookform.shipDayPhone3.value = shipDayPhone3;
document.bookform.shipCellPhone1.value = shipCellPhone1;
document.bookform.shipCellPhone2.value = shipCellPhone2;
document.bookform.shipCellPhone3.value = shipCellPhone3;
document.bookform.shipEmail.value = shipEmail;
   }
}
</script>
 

Thanks

[acoder]

Assuming the first option is the default empty option, set the select object selectedIndex to 0:

selObj.selectedIndex = 0;

[Taylor Smith]

I've tried that but I'm just not sure how exactly to do that within my code and have it work.

[acoder]

Change lines 39/40 to be like 23/4, but replace the billing part with 0, e.g.

document.bookform.shipCountrySelect.selectedIndex = 0;

[Taylor Smith]

Thanks! That's was what i was looking for :)