Properties

Property Type Description
availableClass string Defaults to 'availableValue'
availableLabel string Defaults to 'is available.'
baseClass string Defaults to 'availability'
baseId string A string containing the ID of html element where the response will be placed
location integer Defaults to 1
unavailableClass string Defaults to 'unavailableValue'
unavailableLabel string Defaults to 'is already in use.'
url string A string containing the URL to which the request is sent (Required). Defaults to 'ajax.php'

Example 1

<script type="text/javascript">
$(function(){
	$('#username_1').uniqueField({
		url: 'ajax.php',
		baseId: 'exam_x'
	});
});
</script>

Example 2

<script type="text/javascript">
$(function(){
	$('#username_2').uniqueField({
		url: 'ajax.php',
		baseId: 'exam_y'
	});
	$('#email').uniqueField({
		url: 'ajax.php',
		baseId: 'exam_z'
	});
});
</script>


What do you need?

Markup 
<script type="text/javascript" src="js/jquery.js"></script>
<script type="text/javascript" src="js/jquery.uniquefield.js"></script>
<link type="text/css" rel="stylesheet" href="css/jquery.uniquefield.css" />
ajax.php 
<?php
# Open a connection to a MySQL Server
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link)
{
    die('Could not connect: ' . mysql_error());
}

# Select a MySQL database
$db_selected = mysql_select_db('foo', $link);
if (!$db_selected)
{
    die ('Can\'t use foo : ' . mysql_error());
}

if (isset($_POST['field']) && isset($_POST['value']))
{
	$field = mysql_real_escape_string($_POST['field']);
	$value = mysql_real_escape_string($_POST['value']);

	$result = mysql_query("SELECT COUNT(*) AS `count`
				FROM `table_users`
				WHERE `$field` = '$value'
				LIMIT 1",
			$link) or die(mysql_error());
	if (mysql_fetch_object($result)->count == 0) {
		# Value is available
		echo 1;
	} else {
		# Value is already in use
		echo 0;
	}
}
# Close MySQL connection
mysql_close($link);
?>