Something

CHAT_MAIN, top:
<script type="text/javascript">
<!--
  var refresh_enabled;
  refresh_enabled = true;
  
  function EnableRefresh()
  {
    refresh_enabled = true;
  }
  function DisableRefresh()
  {
    refresh_enabled = false;
  }
  
  function BlockingTimer()
  {
    DisableRefresh();
    window.setTimeout("EnableRefresh()", 10000);
  }

-->
</script>





CHAT_MAIN, replace:
		<td class='alt2' align='left' width='100%' valign='top'>
			<div id='ChatDisplay' style="overflow:auto;height:450px;width:100%;">
			</div>
		</td>

with:
		<td class='alt2' align='left' width='100%' valign='top'>
			<div id='ChatDisplay' onMouseDown='BlockingTimer()' style="overflow:auto;height:450px;width:100%;">
			</div>
		</td>


CHAT_MAIN, replace:
		if (msgrequest.handler.readyState == 4 && msgrequest.handler.status == 200 && msgrequest.handler.responseText);
		{
			document.getElementById('htmlwritein').innerHTML = msgrequest.handler.responseText;
			document.getElementById('ChatDisplay').innerHTML = document.getElementById('ChatPage').innerHTML;
			document.getElementById('UserDisplay').innerHTML = document.getElementById('ChatUPage').innerHTML;
			document.getElementById('total_users').innerHTML = document.getElementById('ChatNUsers').innerHTML;
			document.getElementById('ChatDisplay').scrollTop = 99999;
			setTimeout('requestmsgs()', 2000);


with:
		if (msgrequest.handler.readyState == 4 && msgrequest.handler.status == 200 && msgrequest.handler.responseText);
		{
			if (refresh_enabled) {
				document.getElementById('htmlwritein').innerHTML = msgrequest.handler.responseText;
				document.getElementById('ChatDisplay').innerHTML = document.getElementById('ChatPage').innerHTML;
				document.getElementById('UserDisplay').innerHTML = document.getElementById('ChatUPage').innerHTML;
				document.getElementById('total_users').innerHTML = document.getElementById('ChatNUsers').innerHTML;
				document.getElementById('ChatDisplay').scrollTop = 99999;
			}
			setTimeout('requestmsgs()', 2000);