jQuery1.5.2 attr prop
HTML
<script src="http://code.jquery.com/jquery-1.5.2.js"></script>
<input type="checkbox" id="cb1" checked>
<input type="checkbox" id="cb1" checked><br>
<div id="cb1_txt"></div>
<br><br>
<input type="checkbox" id="cb2" checked="checked">
<input type="checkbox" id="cb1" checked="checked"><br>
<div id="cb2_txt"></div>
JavaScript
$(function(){
var $cb1_attr = $('#cb1').attr('checked');
var $cb2_attr = $('#cb2').attr('checked');
$('#cb1_txt').html(
'attr = '+ $cb1_attr +' ('+ typeof $cb1_attr +')<br>'
);
$('#cb2_txt').html(
'attr = '+ $cb2_attr +' ('+ typeof $cb2_attr +')<br>'
);
});