Integrate paypal

I have successfully integrate paypal account. all is working fine. But I want when the payment successfully transfer then redirect to my site. another question how to get response from paypal? here is my paypal form. Thanks

   `<form action="https://sandbox.paypal.com/cgi-bin/webscr" method="post">  
    <input type="hidden" name="business" value="savife_1314264698_biz@gmail.com ">  
    <input type="hidden" name="cmd" value="_xclick-subscriptions">  
    <input type="hidden" name="item_name" value="Alice's Weekly Digest">  
    <input type="hidden" name="item_number" value="DIG Weekly">  
    <input type="hidden" name="currency_code" value="USD">  
    <input type="hidden" name="notify_url" value="http://localhost/check.php">
    <input type="hidden" name="return" value="http://google.co.in">
    <input type="hidden" name="a3" value="5.00">  
    <input type="hidden" name="p3" value="1">  
    <input type="hidden" name="t3" value="M">  

    <!-- Display the payment button. -->  
    <input type="image" name="submit" border="0" src="btn_subscribe_LG.gif" alt="PayPal - The safer, easier way to pay online">  
    <img alt="" border="0" width="1" height="1" src="https://www.paypal.com/en_US/i/scr/pixel.gif" >  
</form>