var sendReq = getXmlHttpRequestObject();
	var receiveReq = getXmlHttpRequestObject();
	
	//Gets the browser specific XmlHttpRequest Object
	function getXmlHttpRequestObject() 
	{
		var xmlHttp=null;

		try
		{     // Firefox, Opera 8.0+, Safari    
            xmlHttp = new XMLHttpRequest(); 
        }   
        catch (e)
        {   // Internet Explorer   
             
            try
            {
                xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");      
            }
            catch (e) 
            {
                 
                try
                {
                    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");        
                }
                catch (e)  
                { 
                    //document.getElementById('p_status').innerHTML = 'Status: Cound not create XmlHttpRequest Object.  Consider upgrading your browser.';
                }
            }
        }
        return xmlHttp;
	}
			
	//Add a message to the chat server.
	function SendMessage() {
		if(document.getElementById('txt_uname').value == '') {
		    alert("You have not entered a username");
		    return;
		}
		if (sendReq.readyState == 4 || sendReq.readyState == 0) {
			sendReq.open("POST", 'Default_call.aspx?' , true);
			sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
			sendReq.onreadystatechange = handleSent; 
			var param = 'un=' + document.getElementById('txt_uname').value;
			param += '&pw=' + document.getElementById('txt_pword').value;
			sendReq.send(param);
		}						
	}
	
	//When our message has been sent, update our page.
    function handleSent() {
	    getChatText();
    }
    
    //Gets the current messages from the server
	function GetMessage() {
	    if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
			    var param = 'un=' + document.getElementById('txt_uname').value;
			    param += '&pw=' + document.getElementById('txt_pword').value;
			    receiveReq.open("GET", 'Default_call.aspx?' + param, true);
			    receiveReq.onreadystatechange = parseMessage; 
			   receiveReq.send(null);
		}			
	}
			
    //Function for handling the return of chat text
    function parseMessage() {
	    if (receiveReq.readyState == 4) {
	        var result;
	        var time;
	        var errMessage;
	        var videofile;
	        var xmldoc = receiveReq.responseXML;
		    var message_nodes = xmldoc.getElementsByTagName("response"); 
		    var n_messages = message_nodes.length;
		    document.getElementById('txt_pword').value = '';
		    
		    for (i = 0; i < n_messages; i++) {
			    result = message_nodes[i].getElementsByTagName("result");
			    errMessage = message_nodes[i].getElementsByTagName("errmessage");
			    videofile = message_nodes[i].getElementsByTagName("introvideo");
			    time = message_nodes[i].getElementsByTagName("time");
			}
			if(result) {
			    if (result[0].firstChild.nodeValue.toLowerCase() == 'true'){
                    document.getElementById('lblErr').innerHTML = 'Valid Login'; 
                    //document.getElementById('login').style.visibility = 'hidden';
                    window.location = 'Homeroom/Lobby.aspx';
    			
//                    if (videofile[0].firstChild.nodeValue != ''){
//                        playIntroMovie(videofile[0].firstChild.nodeValue);  
//                        document.getElementById('divMain').style.visibility = 'hidden';
//                    }  
			    }	    
			    else{
			       document.getElementById('lblErr').innerHTML = errMessage[0].firstChild.nodeValue; 
			    }
			}
		}
    }
    
    //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() {  
        SendMessage();
        return false;
    }
    
    function playIntroMovie(videoName){
        writeMovie(videoName);
    }
    
    var txt_submit; 
        
    function DetectEnter(e)
    {
        var characterCode;
        if(e && e.which)
        {
            e = e;
            characterCode = e.which;
        }
        else
        {
            e = event;
            characterCode = e.keyCode;
        }
        
        if(characterCode == 13)
        {
            txt_submit.click();
        }
    }