Question

I currently have this code which calculates the total value of checkboxes when they are checked. I need to know how how I would add a radio button selection to this calculation. I need to do this as it adds a total and displays it live.

$(document).ready(function() {
    function recalculate() {
        var sum = 0;
        var base = 0;

        $("input[type=checkbox]:checked").each(function() {
             sum += parseInt($(this).attr("rel"));
        });

        $("#output").html(sum);
    }

    $("input[type=checkbox]").change(function() {
        recalculate();
    });

});


    <td width="236" height="25" align="left">Booking Period:</td>
</tr>
            <tr>
                <td height="10" align="right" class="align_left">One Day: ₤49 </td>
                <td>
                  <input type="radio" name="duration" id="oneday" value="One Day Rental"/>
                </td>
              </tr>

    <tr>
                <td height="30" align="right" class="align_right">Two Day: ₤69</td>
                <td>
                  <input type="radio" name="duration" id="two" value="Two Day Rental"/>
                </td>
              </tr>
    <tr>
                <td height="30" align="right" class="align_right">Weekend: ₤79</td>
                <td>
                  <input type="radio" name="duration" id="weekend" value="Weekend Rental"/>
                </td>
              </tr>

Answer 1

If there is only one radio button group on this page you can simply use :radio[name='duration']:checked to get the currently selected radio button.

function recalculate() {
    var sum = 0;
    var base = 0;

    $("input[type=checkbox]:checked").each(function() {
         sum += parseInt($(this).attr("rel"), 10);
    });

    sum +=  parseInt($(":radio[name='duration']:checked").attr("rel"), 10);  // or some attribute that has the price
    $("#output").html(sum);
}

And than to trigger the recalculate simply add the :radio[name='duration'] selector:

$("input[type=checkbox], :radio[name='duration']").change(function() {
    recalculate();
});

Side note, you should include the radix in parseInt(, 10) to be on the safe side.

Example on jsfiddle