Probleem met else-statement

<?php

if (isset($_POST['uname']) && isset($POST['password']))

//function validate($data)
//{
//$data = trim($data);
//$data = stripslashes($data);
//$data = htmlspecialchars($data);
//return $data;
//}
{
	$uname = $_POST['uname'];
	$pass = $_POST['password'];

	if (empty($uname))
	 	{
			header("location: index.php?error=User Name is required");
			exit();
		}
			else if (empty($pass))
			{
				header("location: index.php?error=Password is required");
				exit();
			}
				else
				{
					echo "Valid input";
				}
	else
	{
		header("location: index.php");
		exit();
	}
}

?>