Shoutbox ajax chỉ load khi có nội dung mới ego

<div id="content">{{message_list}}</div>

<div style="padding: 3px 2px; background-color: white; border: 1px solid#efefef; margin-top: 1px; color: #003399; word-wrap: break-word; text-align: left;">{{nick}}: {{message}}</div>

<div id="time">{{message_list}}</div>

{{message_date|date('U')}}

<script src="/files/1020011/jquery.min.js"></script>
<div style="background: #f5fce2; border: 1px solid #b4e61e; color: #009900; padding: 3px; margin: 1px 1px 1px 1px; text-align: left;">
<form method="post" action="#" id="frm_chat">
Nhập văn bản<br/>
<textarea name="text" id="chat_text"></textarea><br/>
<input type="submit" value="Viết"/>
</form>
</div>
<div id="scontent"></div>
 
<script type="text/javascript">
a=1;
function load_data()
{
$('#scontent').load('/main.php?f=3461643 #content');
}
$('#frm_chat').submit(function(e){
e.preventDefault();
if($('#chat_text').val().length > 0)
{
$.post('main.php?[ses]&id=ch_topic_h&uid=215578&back_url=%2Fmain.php%3Ff%3D3461643',{text:$('#chat_text').val()});
$('#chat_text').val('');
load_data();
}
});
$('#chat_text').keypress(function(e){if((e.keyCode == 10 || e.keyCode == 13) && !e.shiftKey){e.preventDefault();$('#frm_chat').trigger('submit')}})
 
function load(){
$('<div/>').load('/main.php?f=3461645 #time',function(data){
var b=$(data).find('#time').text();
if(a < b)
{
load_data();
a=b;
}
});
}
 
 
$( document ).ready(function(){
load_data();
});
setInterval(function(){load()},1000);
</script>