Ajax - Refresh Chat Not Working

[Spencer]

Hello There!

 

I am trying to get my chat room, to automatically update the messages and data. As of right now, to see a new message, you must refresh the page. ( I learned from w3schools and don't quite get AJAX as much as I want to. :/ So if I'm way off track, please tell me. ) As always, here is the code I am using:

 

&--#60;?php
session_start();
if(!session_is_registered(myusername)){
header("location:/login/main_login.php");
}

$myusername = $_SESSION['myusername'];

?&--#62;




&--#60;html&--#62;
&--#60;head&--#62;
&--#60;link rel="SHORTCUT ICON" href="http://oi46.tinypic.com/rky444.jpg"&--#62;
&--#60;title&--#62;Mbox:Chat&--#60;/title&--#62;

&--#60;script type='text/javascript'&--#62;
function updateChat()
{
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function()
{
if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
{
document.getElementById("topscreen").innerHTML = xmlhttp.responseText;
}
}
xmlhttp.open("GET",/chat/chatroom.php?error=",true);
xmlhttp.send();
}
&--#60;/script&--#62;

&--#60;style&--#62;

/*3DS SCREEN START*/

div#topscreen
{
       border:15px solid;
       border-color:#1E90FF;
       overflow:auto;
position: absolute;
top: 0px;
left: 0px;
height: 205px;
width: 290px;
background-color:#FFFFFF;
z-index:2;

}

div#bottomscreen
{
position: absolute;
top: 218px;
left: 0px;
height: 212px;
width: 320px;
background-color:#1E90FF;

}

/*3DS SCREEN STOP*/

div#taskbar
{
background-color:silver;
width:320px;
height:100px;
position:absolute;
top:30px;
z-index:5;
}

&--#60;/style&--#62;
&--#60;meta name="viewport" content="width=320"&--#62;
&--#60;/head&--#62;
&--#60;body&--#62;

&--#60;body onload="setInterval('updateChat()',5000);"&--#62;

&--#60;!-- TOP SCREEN --&--#62;
&--#60;div id="topscreen"&--#62;

&--#60;?php

$db_sitename="spencer_register";
$db_hostname="localhost";
$db_username="spencer_mega";
$db_password="PASSWORD HERE";
$no_of_comments="15";

/* Leave the script below as it is */
mysql_connect($db_hostname, $db_username, $db_password);
mysql_select_db($db_sitename);
$pagename=md5($_SERVER['PHP_SELF']);
$query=mysql_query("Select * from comments where comment_on='$pagename' ORDER BY id DESC LIMIT 0, $no_of_comments");


while($fetch=mysql_fetch_array($query)) {
echo "&--#60;p&--#62;&--#60;b&--#62;&--#60;sub&--#62;".$fetch['comment_by'].": &--#60;/sub&--#62;&--#60;/b&--#62;&--#60;sub&--#62;".$fetch['comment']."&--#60;/sub&--#62;&--#60;/p&--#62;";
}
mysql_close();
?&--#62;


&--#60;/div id="topscreen"&--#62;

&--#60;!-- BOTTOM SCREEN --&--#62;
&--#60;div id="bottomscreen"&--#62;

&--#60;!-- PUT STUFF ON THE TASKBAR UNDER THE DIV ID TASKBAR --&--#62;
&--#60;div id="taskbar"&--#62;

&--#60;a href="../homepage.php"&--#62;&--#60;img src="http://the12.squarespace.com/storage/zzzzhome.png?__SQUARESPACE_CACHEVERSION=1356027845932" width="50px" height="50px"&--#62;&--#60;/a&--#62;

&--#60;/div id="taskbar"&--#62;
&--#60;!-- Send input box start --&--#62;

&--#60;form action="/chat/post_chat.php" method="post"&--#62;
&--#60;table&--#62;
&--#60;tr&--#62;&--#60;td&--#62; &--#60;/td&--#62;&--#60;td&--#62;&--#60;input type="hidden" name="comment_on" size="" readonly="readonly"  value="&--#60;?php print md5($_SERVER['PHP_SELF']); ?&--#62;"/&--#62;&--#60;/td&--#62;&--#60;/tr&--#62;
&--#60;input type="hidden" name="comment_by"  value="&--#60;?php echo $myusername;?&--#62;"/&--#62;
&--#60;tr&--#62;&--#60;td&--#62;&--#60;input name="comment" size="33" maxlength="255" &--#62;&--#60;input type="submit" value="Send!" /&--#62;&--#60;/td&--#62;&--#60;/tr&--#62;
&--#60;br/&--#62;&--#60;br/&--#62;&--#60;br/&--#62;&--#60;br/&--#62;&--#60;br/&--#62;&--#60;br/&--#62;&--#60;br/&--#62;&--#60;br/&--#62;
&--#60;tr&--#62;&--#60;td&--#62;&--#60;/td&--#62;&--#60;td&--#62;&--#60;/td&--#62;&--#60;/tr&--#62;
&--#60;/table&--#62;
&--#60;/form&--#62;

&--#60;/div id="bottomscreen"&--#62;


&--#60;/body&--#62;
&--#60;/html&--#62;

 

Yeah I know. =P Some messy coding, but I'm working on it.

 

Alright, well thanks in advance!

 

~ Spencer

 

 

[Shinryuu]

Let me know if you still have trouble with this, I'll edit this post with what we talked about in IRC tomorrow.