How to get response from Unsubscribe button from Paypal

Question

Hello All,

 

I am trying to use paypal's unsubscribe button in my website. Below is the format of that button.

 

<a href='https://www.paypal.com/cgi-bin/webscr?cmd=_subscr-find&alias=**Business ID** '>

<img src='https://www.paypalobjects.com/en_US/i/btn/btn_unsubscribe_LG.gif' border='0'>

</a>

 

Now My Requirement is, Once it is unsubscribed successfully, i want to make entry for that specific user in Database.

 

Can anyone please help me how can i implement this scenario ?

 

I am familier with adding entry in database but i am confused about logic how to get success response from above mentioned link. 

 

I have gone through many tutorial but not finding any right approach to implement this. 

 

Thank you in Advance.