How to redirect a page to another page in php?

Redirect a page to another page in php

function logoutpage(){
echo '<script LANGUAGE="JavaScript">window.location.href="'.site_url().'/logout/";</script>';
}

function dashboard(){
echo '<script LANGUAGE="JavaScript">window.location.href="'.site_url().'/dashboard/";</script>';
}

function loginpage(){
echo '<script LANGUAGE="JavaScript">window.location.href="'.site_url().'";</script>';
}

//Ex. code used in logouy page  


<?php
/*
Template Name: Logout
*/

session_start();
session_destroy();
session_unset();
loginpage();
?>
<script>
    location.reload();

</script>