Question

the code for html is :

<div id="container"><h1>Add-ons</h1>
<input type="checkbox" name="ch1" value="10" id="qr1" />Add-on Number 1 - 10 QR <br />
<input type="checkbox" name="ch1" value="20" id="qr1" />Add-on Number 2 - 20 QR <br />
<input type="checkbox" name="ch1" value="40" id="qr1" />Add-on Number 3 - 40 QR <br />
<input type="checkbox" name="ch1" value="60" id="qr1" />Add-on Number 4 - 60 QR <br />
</div>

<div> I want more add-ons
<select id="more" name="more">
    <option value="0 QR">0</option>
    <option value="30 QR">1</option>
    <option value="50 QR">2</option>
    <option value="100 QR">3</option>
</select>
<span id="span"></span>
 User total usage: <span id="usertotal"> </span>

Jquery:

//For select          

      function displayVals() {
      var singleValues = $("#more").val();         
      $("#span").html("<b>more addons:</b> " + 
                  singleValues);
         }

    $("select").change(displayVals);
    displayVals();
//For  checkboxes
var $cbs = $('input[name="ch1"]');
$cbs.click(function() {
    var total = 0;
    $cbs.each(function() {
        if (this.checked)
            var singleValues = $("#more").val();
            total += +this.value + singleValues;
    });
    $("#usertotal").text(total);
});

I want at the user total usage: to create the sum of the checkboxes and add with the value of the option so that if I select 1 checkbox and 2 plus option 1 I will have written in user total usage: 60 .
Thank YOU in advance !

Answer 1

working demo: http://jsfiddle.net/GNDAG/

Hope it helps. You can read more about each here.

However, like @nnnnnn mentioned, your html isn’t right — ID attributes need to be unique.

Code

$('input[type="checkbox"]').change(function() {
   var total_span = 0;
    $('input[type="checkbox"]').each(function() {
        if ($(this).is(':checked')) {
            total_span += parseInt($(this).prop('value'), 10);
        }
    });

    $("#usertotal").html(total_span);
});​