JQUERY复选框CHECKBOX全选,取消全选

<script type="text/javascript">
$(function() {
$("#checkall").click(function() {
$("input[@name='checkname[]']").each(function() {
$(this).attr("checked", true);
});
});
$("#delcheckall").click(function() {
$("input[@name='checkname[]']").each(function() {
$(this).attr("checked", false);
});
});
});
</script>

<input type='checkbox' id='id1' name='checkname[]' value='1' />value1
<input type='checkbox' id='id2' name='checkname[]' value='2' />value2
<input type='checkbox' id='id3' name='checkname[]' value='3' />value3

<input type="button" id="checkall" name="checkall" value="全选" />
<input type="button" id="delcheckall" name="delcheckall" value="取消全选" />