var sendReq = getXmlHttpRequestObject();
var receiveReq = getXmlHttpRequestObject();
var lastMessage = 0;
var mTimer;
//Function for initializating the page.
function startChat() {
//Set the focus to the Message Box.
document.getElementById('txt_message').focus();
//Start Recieving Messages.
getChatText();
}
//Gets the browser specific XmlHttpRequest Object
function getXmlHttpRequestObject() {
if (window.XMLHttpRequest) {
	return new XMLHttpRequest();
} else if(window.ActiveXObject) {
	return new ActiveXObject("Microsoft.XMLHTTP");
} else {
	document.getElementById('p_status').innerHTML = 'Status: Cound not create XmlHttpRequest Object.  Consider upgrading your browser.';
}                                                                                                             
}

//Gets the current messages from the server
function getChatText() {
if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
	receiveReq.open("GET", 'getChat.php?chat=1&last=' + lastMessage, true);
	receiveReq.onreadystatechange = handleReceiveChat;
	receiveReq.send(null);
}
}
//Add a message to the chat server.
function sendChatText() {
if(document.getElementById('txt_message').value == '') {

	return;
}
if (sendReq.readyState == 4 || sendReq.readyState == 0) {
	sendReq.open("POST", 'getChat.php?chat=1&last=' + lastMessage, true);
	sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
	sendReq.onreadystatechange = handleSendChat;
	var param = 'message=' + document.getElementById('txt_message').value;
    param += '&userid='+document.getElementById('userid').value;
	param += '&name='+document.getElementById('username').value;
    param += '&chat_flag='+document.getElementById('chat_flag').value;
	param += '&chat=1';
	sendReq.send(param);
	document.getElementById('txt_message').value = '';
}
}
//When our message has been sent, update our page.
function handleSendChat() {
//Clear out the existing timer so we don't have
//multiple timer instances running.
clearInterval(mTimer);
getChatText();
}
//Function for handling the return of chat text
function handleReceiveChat() {
if (receiveReq.readyState == 4) {
	var chat_div = document.getElementById('div_chat');
	var xmldoc = receiveReq.responseXML;
	var message_nodes = xmldoc.getElementsByTagName("message");
	var n_messages = message_nodes.length
	for (i = 0; i < n_messages; i++) {
		var user_node = message_nodes[i].getElementsByTagName("user");
		var text_node = message_nodes[i].getElementsByTagName("text");
		var time_node = message_nodes[i].getElementsByTagName("time");
		chat_div.innerHTML += user_node[0].firstChild.nodeValue + '&nbsp;';
		chat_div.innerHTML += '[<font class="chat_time">' + time_node[0].firstChild.nodeValue + '</font>]: ';
		chat_div.innerHTML += text_node[0].firstChild.nodeValue + '<br />';
		chat_div.scrollTop = chat_div.scrollHeight;
		lastMessage = (message_nodes[i].getAttribute('id'));
	}
	mTimer = setTimeout('getChatText();',2000); //Refresh our chat in 2 seconds
}
}
//This functions handles when the user presses enter.  Instead of submitting the form, we
//send a new message to the server and return false.
function blockSubmit() {
sendChatText();
//Ajax.Updater('null', 'index.php', {encoding: 'UTF-8',parameters: {info: '1'; userid: document.getElementById('userid').value; username: document.getElementById('username').value; chat_insert: $F('txt_message')}});
return false;
}
//This cleans out the database so we can start a new chat session.
function resetChat() {
if (sendReq.readyState == 4 || sendReq.readyState == 0) {
	sendReq.open("POST", 'getChat.php?chat=1&last=' + lastMessage, true);
	sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
	sendReq.onreadystatechange = handleResetChat;
	var param = 'action=reset';
	sendReq.send(param);
	document.getElementById('txt_message').value = '';
}
}
//This function handles the response after the page has been refreshed.
function handleResetChat() {
document.getElementById('div_chat').innerHTML = '';
getChatText();
}