//index.php
function check_form(url)
	{
	new Ajax.Updater("submit","check_url.php",{method: "POST", parameters: { url_to_check: url } });
	}

function submit(title,description,url)
	{
	new Ajax.Updater("submit","submit.php",{method: "POST", parameters: { submit_title: title, submit_description: description, submit_url: url } });
	}

<div id="submit" >
	<div id="submit_stage1" >
		<form>
		<h5> Enter a URL:</h5>
		<input type="text" name="url" />
		<input type="button" value="Submit" onclick="check_form($F(url))" />
		</form>
	</div>
</div>


//check_url.php
<?php
require_once "include.php";
if(substr($_POST['url_to_check'],0,6)!="http://" || substr($_POST['url_to_check'],0,7)!="https://")
	{
	$clean_url="http://" . $_POST['url_to_check'];
	}
else
	{
	$clean_url=$_POST['url_to_check'];
	}

$check_url_query="SELECT url FROM story WHERE url='" . $clean_url . "'";

$url_result=mysql_num_rows(mysql_query($check_url_query));

if($url_result=="0")
	{
	echo "<div id='submit_stage2' >
			<form>
			<h5><a href='" . $clean_url . "'>" . $clean_url . "</a></h5>
			<h5>Enter a title:</h5>
			<input type='text' name='title' maxlength='85' />
			<h5>Enter a description:</h5>
			<textarea name='description' cols='35' rows='10' maxlength='500'></textarea><br />
			<input type='hidden' name='url' value='" . $clean_url . "' />
			<input type='Button' value='Submit' onclick='submit($F(title),$F(description),$F(url))' />
			</form>
			</div>";
	}
else
	{
	echo "<div id='submit_stage1' >
			<h4>That has already been submitted</h4>
			<form>
			<h5> Enter a URL:</h5>
			<input type='text' name='url' />
			<input type='button' value='Submit' onclick='check_form($F(url))' />
			</form>
			</div>";
	}


?>


//submit.php
<?php
$url=mysql_real_escape_string($_POST['submit_url']);
$title=mysql_real_escape_string($_POST['submit_title']);
$description=mysql real_escape_string($_POST['submit_description']);

$add_query="INSERT INTO story(title, description, url) VALUES ('" . $title . "', '" . $description . "', '" . $url . "')";
mysql_query($add_query);

echo "<div id='submit_stage1' >
		<form>
		<h5> Enter a URL:</h5>
		<input type='text' name='url' />
		<input type='button' value='Submit' onclick='check_form($F(url))' />
		</form>
	</div>"

?>