how to refresh particular div tag content without reloading page using jquery?

// Note : First include jquery.js file.....
<script type="text/javascript">
var auto_refresh = setInterval(
function ()
{
$('#load_div').load('load.php').fadeIn("slow");
}, 100000); // refresh every 10000 milliseconds
</script>

//index.php

<div id="load_div">
</div>

//load.php

In this page you can write your code.
like load randam user,image etc....

How to pass data from one domain to another domain(cross domain) using json?‏

//Javascript code

<script type="text/javascript">

$(document).ready(function()
{

var surl =  "http://www.example.com/json.php";

email_id=document.getElementById("email").value;

$.ajax({
url: surl,
data: {email:email_id},
dataType: "jsonp",
jsonp : "callback",
jsonpCallback: "jsonpcallback"
});
});

function jsonpcallback(rtndata)
{
document.getElementById("disp_data").innerHTML=rtndata.message;
}

</script>

//json.php file code

<?php

$display="<b>HI Json</b>";

$display.="<p>HI This is testing json.</p>";

$rtnjsonobj->message = $display;

echo $_GET['callback']. '('. json_encode($rtnjsonobj) . ')';

?>

error page using htaccess file

first create .htaccess  file and save it.

then write below code

ErrorDocument 404 /404.html

 

here

404 means when page not found then it occurs

404.html means that page which you want to display.