diff --git a/public_html/channel.html b/public_html/channel.html
index c38df9a..247a5a3 100644
--- a/public_html/channel.html
+++ b/public_html/channel.html
@@ -13,9 +13,10 @@
 	<link rel="stylesheet" href="/css/sirc.css" />
 </head>
 <body>
+<a id="dummy" name=""></a>
 <div id="wrapper" data-role="page">
 	<div data-role="header" data-position="fixed" data-theme="d">
-		<a id="update" data-role="button" data-icon="refresh" data-iconpos="notext">update</a>
+		<a id="update" data-role="button" data-icon="forward" data-iconpos="notext">update</a>
 		<h1 id="channel">How to use SIRC</h1>
 		<a id="setting" data-role="button" data-icon="gear" data-iconpos="notext">setting</a>
 		<div id="menu" style="display:none;">
diff --git a/public_html/js/sirc.js b/public_html/js/sirc.js
index f8c7814..c5a635e 100644
--- a/public_html/js/sirc.js
+++ b/public_html/js/sirc.js
@@ -4,30 +4,42 @@
 
 var channel = '';
 var last_update = '';
+var last_downdate = '';
 
 // Utility
 
-var add_process = function(xml) {
+var add_process = function(xml, flag) {
 	$('log', xml).each(function(i) {
-		var flag = $(this).find('flag').text();
 		var datetime = $(this).find('datetime').text();
 		var source = $(this).find('source').text();
 		var message = $(this).find('message').text();
 		append_log(flag, datetime, source, message);
 	});
-	scroll(SCROLL_END);
 	$('ul#log').listview('refresh');
+	if(flag != 'downdate')
+		scroll(SCROLL_END, 1000);
 };
 
 var append_log = function(flag, datetime, source, message) {
-	$('<li><div class="datetime">' + datetime_format(datetime) + '</div><div class="source">&lt;<span class="nick">' + html_encode(source) + '</span>&gt;</div><div class="message">' + html_encode(message) + '</div></li>').appendTo($('ul#log')).attr('flag', flag);
-	if(flag != 'send') last_update = datetime;
+	var element = $('<li><div class="datetime">' + datetime_format(datetime) + '</div><div class="source">&lt;<span class="nick">' + html_encode(source) + '</span>&gt;</div><div class="message">' + html_encode(message) + '</div></li>');
+	if(flag == 'downdate') {
+		element.prependTo($('ul#log'));
+		last_downdate = datetime;
+	}else {
+		element.appendTo($('ul#log')).attr('flag', flag);
+		if(flag != 'send') last_update = datetime;
+	}
 };
 
 var datetime_format = function(datetime) {
 	return datetime.substr(0, 19).replace(' ', '<br />');
 };
 
+var datetime_now = function() {
+	var d = new Date();
+	return d.getFullYear() + '-' + (d.getMonth() + 1) +  '-' + d.getDate() + ' ' + d.getHours() + ':' + d.getMinutes() + ':' + d.getSeconds();
+};
+
 var html_encode = function(s) {
 	var e = document.createElement('div');
 	e.innerText = e.textContent = s;
@@ -37,38 +49,55 @@ var html_encode = function(s) {
 };
 
 var SCROLL_END = -1;
-var scroll = function(pos) {
+var scroll = function(pos, duration) {
 	if($('#scrolling').val() == 'off') return;
 	if(pos == SCROLL_END) pos = $('ul#log').height();
-	$('body,html,document').animate({scrollTop: pos}, 1000);
+	$('body,html,document').animate({scrollTop: pos}, duration);
 };
 
 // Ajax Calls
 
 var sirc_update = function() {
-	$.mobile.showPageLoadingMsg();
+	if(channel == '') return false;
 	$.ajax({
 		type: 'GET',
 		url: '/sgm/update/',
 		data: 'channel=' + encodeURIComponent(channel) + '&last_update=' + encodeURIComponent(last_update),
 		dataType: 'xml',
 		success: function(xml) {
-			add_process(xml);
-			$('a#update').removeAttr('disabled');
+			add_process(xml, 'update');
 			$('ul#log > li[flag="send"]').remove();
+		},
+		error: function(xhr) {
+			alert('update: ' + xhr.responseText);
+		}
+	});
+	return false;
+};
+
+var sirc_downdate = function() {
+	if(channel == '') return false;
+	$.mobile.showPageLoadingMsg();
+	$.ajax({
+		type: 'GET',
+		url: '/sgm/downdate/',
+		data: 'channel=' + encodeURIComponent(channel) + '&last_downdate=' + encodeURIComponent(last_downdate),
+		dataType: 'xml',
+		success: function(xml) {
+			add_process(xml, 'downdate');
+			$('<li>more</li>').click(function() { $(this).remove(); return sirc_downdate(); }).prependTo($('ul#log'));
 			$.mobile.hidePageLoadingMsg();
 		},
 		error: function(xhr) {
-			alert(xhr.responseText);
-			$('a#update').removeAttr('disabled');
+			alert('downdate: ' + xhr.responseText);
 			$.mobile.hidePageLoadingMsg();
 		}
 	});
-	$('a#update').attr('disabled', 'disabled');
 	return false;
 };
 
 var sirc_send = function() {
+	if(channel == '') return false;
 	var message = $('input#message').val();
 	if(message == '') return false;
 	$.ajax({
@@ -77,12 +106,12 @@ var sirc_send = function() {
 		data: 'channel=' + encodeURIComponent(channel) + '&message=' + encodeURIComponent($('input#message').val()),
 		dataType: 'xml',
 		success: function(xml) {
-			add_process(xml);
+			add_process(xml, 'send');
 			$('input#message').val('');
 			$('form#send').removeAttr('disabled');
 		},
 		error: function(xhr) {
-			alert(xhr.responseText);
+			alert('send: ' + xhr.responseText);
 			$('form#send').removeAttr('disabled');
 		}
 	});
@@ -93,10 +122,12 @@ var sirc_send = function() {
 var sirc_join = function() {
 	if(!window.location.hash) return;
 	channel = window.location.hash;
+	$('a#dummy').attr('name', channel.substr(1))
 	$('title').html(channel + ' - SIRC');
 	$('h1#channel').html(channel);
 	$('ul#log').empty();
-	last_update = '';
+	last_update = last_downdate = datetime_now();
+	sirc_downdate();
 	sirc_update();
 	return false;
 };
diff --git a/public_html/result.xml b/public_html/result.xml
index 0b55677..45011a7 100644
--- a/public_html/result.xml
+++ b/public_html/result.xml
@@ -2,7 +2,6 @@
 <result>
 	{% for log in logs %}
 		<log>
-			<flag><![CDATA[{{ log.flag }}]]></flag>
 			<datetime><![CDATA[{{ log.datetime }}]]></datetime>
 			<source><![CDATA[{{ log.source }}]]></source>
 			<message><![CDATA[{{ log.message }}]]></message>
diff --git a/wsgi.py b/wsgi.py
index 416b71e..f1be73f 100644
--- a/wsgi.py
+++ b/wsgi.py
@@ -1,7 +1,7 @@
 # coding: utf-8
 
 import datetime
-import gevent
+import gevent # not used yet
 import os
 import re
 import sys
@@ -48,6 +48,8 @@ def application(environ, start_response):
 
 	if path.startswith('/update/'):
 		return update(environ, start_response, session, parameters)
+	elif path.startswith('/downdate/'):
+		return downdate(environ, start_response, session, parameters)
 	elif path.startswith('/send/'):
 		return send(environ, start_response, session, parameters)
 	else:
@@ -101,13 +103,36 @@ def update(environ, start_response, session, parameters):
 	context = {}
 	if 'channel' not in parameters:
 		return error(start_response, message = 'no channel')
-	last_update = datetime.datetime.now() - datetime.timedelta(1)
+	last_update = datetime.datetime.now()
 	if 'last_update' in parameters:
-		last_update = datetime.datetime.strptime(parameters['last_update'][0].decode('utf-8'), '%Y-%m-%d %H:%M:%S.%f')
+		last_update = parse_datetime(parameters['last_update'][0].decode('utf-8'))
 	channel = parameters['channel'][0].decode('utf-8').lower()
 	logs = db[channel].find({
 		'datetime': {"$gt": last_update},
-	}).sort('datetime')
+	}, sort = [
+		('datetime', pymongo.ASCENDING)
+	])
+	logs = list(logs)
+	for log in logs:
+		log['source'] = remove_invalid_utf8_char(log['source'])
+		log['message'] = remove_invalid_utf8_char(log['message'])
+	context['logs'] = logs
+	start_response('200 OK', [('Content-Type', 'text/xml; charset=utf-8')])
+	return [render('result.xml', context)]
+
+def downdate(environ, start_response, session, parameters):
+	context = {}
+	if 'channel' not in parameters:
+		return error(start_response, message = 'no channel')
+	last_downdate = datetime.datetime.now()
+	if 'last_downdate' in parameters:
+		last_downdate = parse_datetime(parameters['last_downdate'][0].decode('utf-8'))
+	channel = parameters['channel'][0].decode('utf-8').lower()
+	logs = db[channel].find({
+		'datetime': {"$lt": last_downdate},
+	}, limit = config.N_LINES, sort = [
+		('datetime', pymongo.DESCENDING)
+	])
 	logs = list(logs)
 	for log in logs:
 		log['source'] = remove_invalid_utf8_char(log['source'])
@@ -133,7 +158,6 @@ def send(environ, start_response, session, parameters):
 		'datetime': {'$lt': datetime.datetime.now() - datetime.timedelta(1)}
 	})
 	context['logs'] = [{
-		'flag': 'send',
 		'source': config.BOT_NAME,
 		'message': '<%s> %s' % (remove_invalid_utf8_char(session['account']), remove_invalid_utf8_char(message)),
 		'datetime': datetime.datetime.now()
@@ -162,6 +186,12 @@ def create_session_id(): # TODO: 중복 체크
 	bag = string.ascii_uppercase + string.ascii_lowercase + string.digits
 	return ''.join(random.sample(bag * 24, 24))
 
+def parse_datetime(s):
+	if '.' in s:
+		return datetime.datetime.strptime(s, '%Y-%m-%d %H:%M:%S.%f')
+	else:
+		return datetime.datetime.strptime(s, '%Y-%m-%d %H:%M:%S')
+
 def request_request_token():
 	import oauth2
 	import httplib2
