I have used the following code to take a user from order.html to the PayPal payment page:
header("Refresh: 0;url=https://www.paypal.com/subscriptions/business=sales%40ewebis.com&item_name=$package&no_note=1¤cy_code=GBP&lc=US&a3=$price&p3=1&t3=M&src=1&sra=1");
For some reason after $package it stops and doesn't echo the rest of the URL.
Regards,
-Chris