Ajax :: How To Update Multiple DIVs Accordingly

I am creating a form. The form uses variable to show different divs. Like for example .
If the user chooses state where tax will be implemented than it will update the div which contain total amount. Now the problem is I have 3 divs on a page and I want to update all of them accordingly. Like user select quantity as 500, state as florida. So I need to update 3 divs .. total cost, Shipping cost and quantity divs. Problem is they all r not inside a single div else I would have put tht whole div inside the response. So is there a way to update multiple divs?

Below id the ajax code I am using ..
Code:
function update_dockcontent() {
var quantityval = document.HVAC_Cards_Form.Quantity.value;
var BillingZip = document.HVAC_Cards_Form.BillingZip.value;
var url = '[URL]'+quantityval+'&BillingZip='+BillingZip;
if (window.XMLHttpRequest) {
req = new XMLHttpRequest();
if (req.overrideMimeType) {
req.overrideMimeType('text/xml');
} .....

Code for ajaxcall page is:
Code:
<?
header("Cache-Control: no-cache");
header("Pragma: no-cache");
$total=($_GET[qval]*0.50);
$shippingrate="50";
if($_GET[BillingZip]) {
$total=$total+$shippingrate;
}?>
<p>Total Quantity: <strong><?=$_GET[qval]?></strong></p>
<p>Shipping: <strong><?=$shippingrate?></strong></p>
<p>Total cost: <strong>$<?=number_format($total,2)?></strong></p>
I want to show all 3 of them in different divs.