registration.js

<?php
	mysql_connect("localhost", "root", "") or die(mysql_error());
	mysql_select_db("unity") or die(mysql_error());

	$Username = mysql_real_escape_string($_POST['username']);
	$Email = mysql_real_escape_string($_POST['email']);
	$Password = mysql_real_escape_string($_POST['password']);

	//	Check to see if the user exits.
	$check = mysql_query("SELECT * FROM `members` WHERE username='$Username'");
	$rows = mysql_num_rows($check);

	//	if the user does not exit, then create them.
	if($rows == 0)
	{
		//	Encrypts the users password
		$Password = md5($Password);

		//	Inserts the data into the table
		$createuser = mysql_query("INSERT INTO `members` (username, email, password) VALUES ('$Username', '$Email', '$Password')");

		if($createuser)
		{
			echo "Account Created!";
		}
	}
	else
	{
		$result = mysql_query("SELECT * FROM members") or die(mysql_error());
		$row = mysql_fetch_array( $result );

		while($row = mysql_fetch_array( $result ))
		{
			$user = $row['username'];
			$email = $row['email'];

			if($Username == $user)
			{
				die("Username already in use!");
			}

			if($Email == $email)
			{
				die("Email already in use!");
			}
		}
	}
?>