JavaScript - Tag Is Displaying As Null Although It Isnt

$(document).ready(function(){
	
	var Cycle = setInterval('cycle()', 3000);
	
	/* ... some other functions here ... */
   
	$('.Test').click(function(){
		var ID = $(this).attr('ID');
		clearInterval(Cycle);
                /* ... Rest of this function ... */
                if (ID == 'Home')
		{
			var Cycle = setInterval('cycle()', 3000);
		}
		console.log(ID);
        });
});

Error ``user_node[0].firstChild is null'' [x-] in  file ``*url removed*'',  line 63, character 0.

function manageMessage() {
            if( receiveReq.readyState == 4 ) {  // request complete
                var chat_div = document.getElementById( 'chat' );
                var xmldoc = receiveReq.responseXML;
                var msg_nodes = xmldoc.getElementsByTagName( 'message' );
                var n_msg = msg_nodes.length;
                for( i = 0; i < n_msg; i++ ) {
                    alert(i + "," + n_msg);
                    var user_node = msg_nodes[ i ].getElementsByTagName( 'user' );
                    var time_node = msg_nodes[ i ].getElementsByTagName( 'time' );
                    var text_node = msg_nodes[ i ].getElementsByTagName( 'text' );
                    alert(user_node[0].firstChild.nodeValue);
                    
                    //Display message
                    chat_div.innerHTML += user_node[ 0 ].firstChild.nodeValue + "<br />";
                    chat_div.innerHTML += time_node[ 0 ].firstChild.nodeValue + "<br />";
                    chat_div.innerHTML += text_node[ 0 ].firstChild.nodeValue + "<br /><br />";
                }
            }
        }

<script type="text/javascript">
    //Credits//
    //Help: Greg (Gjslick)
    //Code example: http://www.dynamicajax.com/fr/AJAX_Driven_Web_Chat_Backend-271_290_291_296.html
    
        // Declare Global Variables
        var lastMess;
        var sendReq;
        var receiveReq;
        var mTimer;
        
        // Initialize Global Variables (on page load)
        function init() {
            lastMess = 0;
            sendReq = getXmlHttpRequestObject();
            receiveReq = getXmlHttpRequestObject();
            mTimer;
        }
        
        
        function getXmlHttpRequestObject() {
            if( window.XMLHttpRequest ) {
                return new XMLHttpRequest();    // code decent browsers like Firefox, Chrome, Opera, Safari. And IE7+...
                
            } else if( window.ActiveXObject ) {
                return new ActiveXObject( 'Microsoft.XMLHTTP' );    //Code for crap like IE
                
            } else {
                var statusEl = document.getElementById( 'p_status' );
                statusEl.innerHTML = "Status: Could not create XmlHttpRequest Object, please upgrade your browser!";
                
                return null;
            }
        }
        
        function getMessage() {
            //var url = "scripts/get_data.php?uid=<?=$uid?>&m=" + lastMess + "&chat=1";
            var url = "testXMLdoc.xml";
            receiveReq.open("GET",url,true);
            receiveReq.onreadystatechange = manageMessage;
            receiveReq.send( null );
            lastMess++;
        }
        
        function manageMessage() {
            if( receiveReq.readyState == 4 ) {  // request complete
                var chat_div = document.getElementById( 'chat' );
                var xmldoc = receiveReq.responseXML;
                var msg_nodes = xmldoc.getElementsByTagName( 'message' );
                var n_msg = msg_nodes.length;
                for( i = 0; i < n_msg; i++ ) {
                    alert(i + "," + n_msg);
                    var user_node = msg_nodes[ i ].getElementsByTagName( 'user' );
                    var time_node = msg_nodes[ i ].getElementsByTagName( 'time' );
                    var text_node = msg_nodes[ i ].getElementsByTagName( 'text' );
                    alert(user_node[0].firstChild.nodeValue);
                    
                    //Display message
                    chat_div.innerHTML += user_node[ 0 ].firstChild.nodeValue + "<br />";
                    chat_div.innerHTML += time_node[ 0 ].firstChild.nodeValue + "<br />";
                    chat_div.innerHTML += text_node[ 0 ].firstChild.nodeValue + "<br /><br />";
                }
            }
        }
    </script>

<?xml version="1.0" ?>
<root>
    <message id="1">
        <user></user>
        <text>testing stupid chat thing</text>
        <time>0000-00-00 00:00:00</time>
    </message>
    <message id="2">
        <user></user>
        <text>dsadasfsdfsggsdgrgsdgfd</text>
        <time>2010-04-22 19:17:16</time>
    </message>
</root>

document.getElementById('year').options[i] = new Option(curr_year-i,curr_year-i);

var startnum = readCookie('a1');
if (document.cookie.indexOf('a1') == -1){
var startnum = "0";
}

if (document.cookie.indexOf('a1') == null){

function display_form(id) {
	//Create some variables
	var html = "";
	var container = "form_container";
	var menu = load_menu(id, false);

	//Get id
	 for ( var i = 0; i < menu.length; i++ ) {  
		alert(i);
	}
	
	http = getHTTPObject();
	http.onreadystatechange = function() {
		if ( http.readyState == 4 && http.status == 200 ) {
			document.getElementById(container).innerHTML = http.responseText;
		} else {
			document.getElemenyById(container).innerHTML = "Loading...";
		}
	}
	http.open( "GET", "includes/forms.php?form=" + id );
	http.send();
		
	//Watch input fields 
	//login_listener();
}/*

function load_menu(menu, return_d) {
	//Availible menus
	var data = [];
	data [ 'login' ] = [ 'Login', 'Register', 'Recovery' ];
	data [ 'settings' ] = [ 'Profile', 'Account', 'something' ];
	
	 if (return_d == false) {
		return data[ menu ]; 
	} else {
		//Menu container ID's
		var cons = Array('menuitem1','menuitem2','menuitem3');
	
		for ( var i = 0; i < cons.length; i++ ) {
			document.getElementById(cons[i]).innerHTML += data[ menu ] [ i ];
		}
	}
}

function doLoad(url) {
	
      var iFrameContent = document.getElementById('iframeContenido');
	  iFrameContent.document.getElementsByName('statuszone') = url;
	return;
  }

	var myValue = null;
	var myResult = "unknown";
	if (myValue == null) {
		myResult == "isNull";
	};
	alert("value: " + myValue
		+ "\nresult: " + myResult
	);

 <script language="JavaScript" type="text/javascript">
  maxlen = 160;
  countLen();
	function countLen()
	{
		message_text = window.document.sendform.message_text.value;
		realLength = message_text.length;
		if (realLength>maxlen)
		{
			realLength = maxlen;
			window.document.sendform.message_text.value = message_text.substring(0,maxlen);
		}
		message_text = window.document.sendform.message_text.value;
		// del enter
    var m = message_text.match(/[\r\n]/);
    if (m !== null)
    {
        window.document.sendform.message_text.value = message_text.replace(/[\n\r]/g, '')
    }
		window.document.sendform.messlen.value=maxlen-realLength;
	}
	
</script>

 
 <cfset thismessage = "Hi, is this a start">
 
 
 
 <cfform action="step2.cfm" method="post" id="sendform" name="sendform">
 <cfoutput><textarea id="styled" name="message_text" onkeypress=countLen() onkeydown=countLen() onkeyup=countLen() onchange=countLen() onmouseover=countLen() rows="4">#thismessage#</textarea></cfoutput>
<table width="331" border="0" cellpadding="0" cellspacing="0">
  <tr>
    <td width="5"></td>
    <td width="26"><cfoutput>
      <input name="messlen" type="text" value="160" class="counterField" onFocus="this.form.message_text.focus();" /></cfoutput></td>
    <td width="300">characters remaining</td>
  </tr>
</table>
</cfform>