关于jquery和xml交互显示的有关问题

<?xml version="1.0" encoding="UTF-8"?>
<DiskInfo>
    <disk>
        <DiskNO>1</DiskNO>
        <size>22</size>
    </disk>
    <disk>
        <DiskNO>2</DiskNO>
        <size>33</size>
    </disk>
    <disk>
        <DiskNO>3</DiskNO>
        <size>44</size>
    </disk>
</DiskInfo>

<script>
$.ajax({
        url:"<?php echo $DaemonPath['DISK_INFO'];?>",
        type:"POST",
        dataType: "xml",
        error: function(xml){    
            alert('Error loading XML document'+xml);    
        },
        success: function(data)
        {
            var msg = '';
            $(data).find('disk').each(function(){
                var DiskNO = $(this).children("DiskNO").text();
                var size = $(this).children("size").text();
                msg += '<option value="'+DiskNO+'">disk'+DiskNO+'</option>';
            })
            $('#disk').html(msg);
            //$('#AllRemainSpace').html($('#disk').val());
            $('#disk').click(function(){
                //$('#AllRemainSpace').html($('#disk').val());
            });
        }
    });
</script>

<td width="65%" height="30" align="left" bgcolor="#D9E1E1" style="padding-left:5px;">
    <select name="disk" id="disk">
    </select>
</td>
<td height="30" align="left" bgcolor="#D9E1E1" style="padding-left:5px;"><div id="AllRemainSpace"></div></td>