JavaScript - About Checking For Null Value

Hi
I've implemented Busybox on a website to display FLV files in a popup player. This works fine, except for the following error in IE (FF is fine) when I close the popup: 'null' is null or not an object

I think I've narrowed it down to the following block of code, but am stuck as to what to do from here.

Code:

var cl = new Element('img',{
		'styles':{
			width:'24px',
			height:'24px',
			position:'absolute',
			top:'-20px',
			right:'-20px',
			'z-index':'100000'
		},
		'src':'bumpbox/closed.png',
		'id':'closer'
	})

cl.addEvent('click',function(e){
			e = new Event(e).stop();
		
			bg.dispose();
			$(el).getChildren().dispose();
			eff2.start({
			  'width':[maxw,1],
			  'height':[maxh,1],
			  'left': [endleft,middleH],
			  'top':  [endtop, middleV+s]
			 })
		})

The IE error is just giving me line number 1 of the php, but the error, I'm sure, lays in the Javascript.

Many thanks

I know that unlike PHP, NULL in JavaScript must be quoted as a string. Does it matter if you use single or double quote?

I'm guessing this question will be one of the easiest questions ever posted but I'm just not getting this fix. I have a simple Javascript program that calculates a users pace for their run. The inputs are done through an HTML Form.

The user can input hours, minutes, & seconds of their run. Then the distance number & measurment. Then finally the pace desired. I am having some trouble with null values in this program. If I input a 0 in hours and then fill everything out the program works great. 100%! But, if I leave the field blank and hit calculate I get a NaN. I'm guessing I need some kind of statement like if this value is null set it to zero but I am not having any luck with exactly what kind of syntax I need. So here is the code, again not very complex, any help would be greatly appreciated!


function calculateTime(){
var time_hour = parseInt(document.getElementById("time_hour").value);
var time_min = parseInt(document.getElementById("time_minute").value);
var time_sec = parseFloat(document.getElementById("time_second").value);
var dist_num = parseFloat(document.getElementById("dist_num").value);
var pace_choice = document.getElementById("pace_choice").selectedIndex;
var dist_choice = document.getElementById("dist_choice").selectedIndex;
var total_sec = (time_hour * 3600) + (time_min * 60) + (time_sec);

// Then I'm guessing my if statement would go here somewhere?

On my site I have a Javascript error in my FireBug console:

Year is 'null'

Code:

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

here is my site:
http://harveys.blueplanetdns.com/harveys-shop/

For some reason i'm getting the error of "length is null". Which is from this .

Code:

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();
}/*

Here is the function:
Code:

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 ];
		}
	}
}

Extra info:
id = login
menu = login

New problem, taken from another website I posted this on:

Error:
Code:

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

As you can see it says that the value is NULL although it shouldn't be... Here is the JavaScript which the error refers to:
Code:

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 />";
                }
            }
        }

And again, the whole script if you want it...


Code:

<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>

And here is the XML file (test doc for now):
Code:

<?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>

Bonjour all. I am trying to activate a function once an iframe is closed. so i am trying to use: window.opener.pageUpdate(); which i get an error of

Error: window.opener is undefined
Source File: https://web111.secure-secure.co.uk/s...js/thickbox.js
Line: 270

Which lead me to believe that my parent window has not got a name so i used
window.name = "main"; in my parent and window.main.pageUpdate(); in the child and get same kind of error. Could someone please help me out!

Hi,

I'm trying to build this grease monkey script, which runs on all pages, and simply deletes all iframes that have no content loaded in them.

I have a hosts file with many ad servers which are blocked. This leaves ugly holes in the page and I am trying to remove these empty iframes.


Plz help

Hello,

I'm working on web apps for a company and unfortunately the websites work in Mozilla, chrom and IE9 but not in IE8.

In IE8 the error message "undefined is null or not an object" is pointing to this line:

temp = val.replace(/-/g, "/");

That line is inside a function. I'm not sure how to troubleshoot this...any help would be appreciated.

Hi All,

This code returns "result: unknown". A successful check for null should return "result: isNull".

Suggestions?

Code:

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

Hi....I have an error in my script, but idk where it is..... here is the script:

Code:

<script type="text/javascript">
var browser = navigator.appName;
if (browser=="Netscape") {
document.getElementById(msg).style.display="none";
}
</script>
<div id="msg" style="width:100%;padding:3px;position:fixed;top:0px;left:0px;background:red;">Please install <a href="http://www.mozilla.org/sk/firefox/">Mozilla Firefox</a> to view this page normally.</div>

I cant figure out why this doesnt work - Firefox says:
Error: document.getElementById("test") is null
Source File: file:///Users/briantoovey/test.html
Line: 10

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>Rotating Quotes</title>
</head>
<body>
<script type="text/javascript">
document.getElementById("test").innerHTML = 'eat it';
</script>
<div id="test"></div>
</body>
</html>

Hi,

I am getting an error on this code - sometimes! - and I'm not sure what it is. If I run this as is there is no error. If I add it into another page with other stuff it's ok for a while and then I get an error. So, I added my new page block my block to this code and waited for the error to appear so I could determine a conflict - but it was fine. And then a few clicks later the error.

This is the error in IE. In Firefox it seems to be fine lol.

Line 159
Char 3
'window.document.sendform.message_text' is null or not an object

Can someone make any suggestions?

Code:

 <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>

Thanks! Much appreciated!

Kind regards,

jo

Problem/Error: JavaScript/AJAX not returning values correctly...

The JavaScript/AJAX is printing "null" into the chat_div where the tag name is "user". But in those tags there is actually data, this data is a link. I am thinking that it may be returning the first childNode which would be the <a>? I don't fully understand nodes, but I have had a quick read about them.

PHP:
PHP Code:
<?php
//Headers
header("Expires: Mon, 01 Dec 1990 05:00:00 GMT" );
header("Last-Modified: " . gmdate( "D, d M Y H:i:s" ) . "GMT" );
header("Cache-Control: no-cache, must-revalidate" );
header("Pragma: no-cache" );
header("Content-Type: text/xml; charset=utf-8");

require("connect.php");
mysql_select_db($dbname, $con);

//Variables
$ses = explode(".", $_SESSION['user']);
//User ID of user currently logged in
$sid = $ses[2];

//Number of last message which was displayed, if does not exist or has no value then
//last message will be 0.
$last_mess = (isset($_GET['m']) && $_GET['m'] != "") ? $_GET['m'] : 0;
$last_mess = mysql_real_escape_string($last_mess);

$chat = mysql_real_escape_string($_GET['chat']);
//Counter for counter number of errors
$i = 1;

//Send message
if (isset($_POST['message']) && $_POST['message'] != "") {
    //Variables
    $chat = mysql_real_escape_string($_GET['chat']);
    $message = mysql_real_escape_string($_GET['message']);
    
    $query = "INSERT INTO message (chat_id, user_uid, recipient_uid, message, post_time) VALUES (".
             $chat.", ".$sid.", ".$rid.", ".$message.", NOW())";
    mysql_query($query);
}

//Get current chat
if (isset($_GET['chat'])) {
    $xml = '<?xml version="1.0" ?><root>';
    $query = "SELECT * FROM message WHERE chat_id = ".$chat." AND msg_id > ".$last_mess;
    $result = mysql_query($query);
    while ($row=mysql_fetch_array($result)) {

        //Get name of sender
        $get_name_query = "SELECT * FROM users WHERE uid = '".$row['user_uid']."'
                           OR uid = '".$row['recipient_uid']."'";
        $get_name = mysql_query($get_name_query);
        if (!$get_name) { //If there is no result display error
            echo "Error $i: Error getting usernames! <br /> Query: $get_name_query <br />MySQL Error: ".mysql_error().
                 "<br /><br />";
            $i++;
        }
        //While result is being got get first name and upper case first letter.
        while ($row2=mysql_fetch_array($get_name)) {
            $name = explode(".",$row2['full_name']); $first_name = $name[0];
            $userid = $row2['uid'];
            $sent_by = "<a href=\"../profile.php?user=".$userid."\">".ucfirst($first_name)."</a>";
        }
    
        //Write message contents
        $xml .= '<message id="' . $row['msg_id'] . '">';
        $xml .= '<user>' . $sent_by . '</user>';
        $xml .= '<text>' . $row['message'] . '</text>';
        $xml .= '<time>' . $row['post_time'] . '</time>';
        $xml .= '</message>';
    }
    $xml .= '</root>';
    echo $xml;
}
?>

JavaScript/AJAX:
Code:

function getMessage() {
    if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
        var url = "scripts/get_data.php?uid=<?=$uid?>&m=" + lastMess + "&chat=1";
        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++ ) {
            var user_node = msg_nodes[ i ].getElementsByTagName( 'user' );
            var time_node = msg_nodes[ i ].getElementsByTagName( 'time' );
            var text_node = msg_nodes[ i ].getElementsByTagName( 'text' );
            //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 />";
        }
    }
}

More info:
The PHP is displaying the data properly, like so:

XML:
Code:

<root>
    <message id="1">
        <user>
           <a href="../profile.php?user=4">Nicholas</a>
        </user>
        <text>testing stupid chat thing</text>
        <time>0000-00-00 00:00:00</time>
    </message>
    <message id="2">
        <user>
           <a href="../profile.php?user=4">Nicholas</a>
        </user>
        <text>dsadasfsdfsggsdgrgsdgfd</text>
        <time>2010-04-22 19:17:16</time>
    </message>
    <message id="3">
        <user>
           <a href="../profile.php?user=4">Nicholas</a>
        </user>
        <text>gfgdgsegegsgfawdfwdfasfa</text>
        <time>2010-04-14 17:28:07</time>
    </message>
</root>

What is being displayed on the page:
Code:

null
0000-00-00 00:00:00
testing stupid chat thing

null
2010-04-22  19:17:16
dsadasfsdfsggsdgrgsdgfd

null
2010-04-14 17:28:07
gfgdgsegegsgfawdfwdfasfa