I recommend using .htaccess. Instead of meta refresh.
Adding the redirect in .htaccess instead have many benefits:
No changes of template files. No delays, no problem with back etc.
Line to add in .htaccess:
Redirect 301 /checkout.php
http://www.domain.com/order_info.php
Be careful while updating, so no existing cofig get impacted. Test all .htaccess settings. e.g. friendly urls, 404 page etc.
My file looklike this:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /friendly_url.php [L]
</IfModule>
Redirect 301 /checkout.php
http://www.domain.se/order_info.php
Except the domain, which I change for the example.