<script type="text/javascript">
    function setAllCheckboxes(divId, sourceCheckbox) {
    divElement = document.getElementById(divId);
    inputElements = divElement.getElementsByTagName('input');
    for (i = 0; i < inputElements.length; i++)
{
        if (inputElements[i].type != 'checkbox')
            continue;
        inputElements[i].checked = sourceCheckbox.checked;
    }
}
</script>

<li><input type="checkbox" class="focusable"
onfocus="parentFocus(event)" onblur="parentBlur(event)"
value="my data"><label>label text</label></li>

<input type="checkbox" class="focusable all" onfocus="parentFocus(event)" onblur="parentBlur (event)" onChange="setAllCheckboxes('playlist', this);" />Select All</li>

//![CDATA[
  $(function(){
  $('.button').click(function(event) {
   event.preventDefault();
    if ($("#TextToSave").text() == "type your text here ...") {
      $("#TextToSave").text($(this).html());
    } else {
     $("#TextToSave").text($("#TextToSave").text() + $(this).html() +'</track>');
    }
  });
});]]

<script type="text/javascript">
function doSomething()
{
    var result=document.getElementById('result');
    var global=document.getElementById('global');
    var ul=document.getElementById('ul');
    var input=ul.getElementsByTagName('input');

    result.innerHTML='Result: ';

    for (var i=0; i<input.length-1; i++) // -1 because last INPUT is the global toggle
    {
        if(global.checked)
        {
            input[i].checked=true;
        }

        if(input[i].checked)
        {
            result.innerHTML+=input[i].value;
        }
    }
}
</script>

<ul id="ul">
<li><label><input type="checkbox" value="my data1" onchange="doSomething();">label text</label></li>
<li><label><input type="checkbox" value="my data2" onchange="doSomething();">label text</label></li>
<li><label><input type="checkbox" id="global" onchange="doSomething();">check all</label></li>
</ul>

<p id="result">Result: </p>