$("input[name='all']").change(function(){
var parent = $(this);
$("input[name='"+parent.val()+"[]']",parent.parents('form:first')).each(function(){$(this).attr('checked',parent.is(':checked'));});
});

All you need to use it is the following HTML code.

<form>
<input type="checkbox" name="all" value="myitems">
<input type="checkbox" name="myitems[]" value="1">
<input type="checkbox" name="myitems[]" value="2">
<input type="checkbox" name="myitems[]" value="3">
</form>

So when the user clicks on the check box with name all, all check boxes with the name specified in the value attribute of this ‘all‘ check box will be toggled. I hope someone finds it helpful.