Q:

Popup window when checkbox has not been checked

Is this jQuery, or JavaScript? My assignment disallows the use of jQuery.
function calculateTotal() {
    var collection = document.getElementsByName('deliveryType'),
        cds = document.getElementsByName('cd[]'),
        cdTotal = 0,
        L = collection.length;

    while(L--) {
        if(collection[L].checked) {   // get shipping costs
            collection = Number(collection[L].getAttribute('title')); 
            break;
        }
    }

    L = cds.length;
    while(L--) {
        if(cds[L].checked) {    //add total prices
            cdTotal += Number(cds[L].getAttribute('title'));
        }
    }

    //  output total
    document.getElementById('total').value = collection + cdTotal;
}

A:

This is pure javascript - if you're not sure just look for the inclusion of jQuery somewhere.  It usually looks like this:
<script type="text/javascript" src="jquery.js"></script> 
you could also check what resources are loaded by pressing F12 in your browser.

