First of all refreshing a page every 10 seconds takes less bandwidth then your community constantly hitting pages around your CMS. So compared to the other in coming traffic servers will have, this is nothing. It is a waste, but it doesn't "kill" or "drain" anything to a significant degree.
This release it self is pointless because all you are doing is showing the chat logs in-game? A "Live Chat" is a way of communicating with another person through AJAX (no page refreshing).
If you were to actually make something like this, it would look like this:
Code:
<html>
<head>
<title>Live Chat</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.5.1.min.js"></script>
<script type="text/javascript">
function Initiate()
{
Intervals();
}
function Intervals()
{
setInterval("getChat()", 100);
}
function getChat()
{
$.ajax({
url: "url of page returning all chat logs",
type: "GET",
cache: false,
async: false,
success: function(data)
{
$("div where you want chat to appear").html(data);
}
});
}
windows.onload = Intervals;
</script>
</head>
<body>
HTML form for the inputing of the chat and outputting
</body>
</html>
Something like that ^.