สอบถามเรื่อง checked ajax&jquery

<div class="btn-group" id="Share">
  <button class="btn" type="button" rel="Y"><i class="icon-thumbs-up"></i> Share</button>
  <button class="btn" type="button" rel="N"><i class="icon-thumbs-down"></i> UnShare</button>
  <input type="checkbox" id="chkShare" />
</div>
<script src="jquery10-2.js"></script>
	<script>
		$(function(){
			$('#Share button').click(function(){
				var rel=$(this).attr('rel');
				var chkShare=$('#chkShare');
				$('#Share button').removeClass('btn-success');
				$(this).addClass('btn-success');
				if(rel == 'Y'){
					chkShare.attr({'checked':true});
				}else if(rel=='N'){
					chkShare.removeAttr('checked');	
				}
			});			
		});
	</script>