PayPal IPN Script not Redirecting to ipn.php

I have downloaded the sample paypal IPN script using php and customised with the email for the buyout option and it has also some hidden paramaters such amount, quantity,return_url, notify_url like this.After the success payment in the sandbox ur开发者_StackOverflow社区l,it doesn't redirect to the ipn.php to make database insertion for successful transaction.

My site url: http://anderson.000space.com/paypal_ipn/example-form.html

I have given the notify url for IPN in my paypal sandbox merchant account as http://anderson.000space.com/paypal_ipn/ipn.php. I have printed some values there and given exit in that page, but the redirection from paypal is not going to ipn.php.

IPN is not the redirection page. "return" controls which page they're redirected back to, "notify_url" (IPN) is the script that receives a POST from PayPal with transaction information.