title: Paypal: email a payment link & callback
body: <p>Using Paypal, what is the easiest way to create a page on which a user can pay a specific amount determined by me?</p>
  
  <p>Basically, a request for a service is displayed in a custom CMS and the system calculates the price automatically. The admin reviews the price and then clicks a button to send a link to the requester via which they make the payment.</p>
  
  <p>There is no shopping cart, no shipping details, no quantities, the "look" of the payment page is not important. After the payment is done I'd like to receive a callback to notify me of the payment.</p>
  
  <p>What's the best way to go about this?</p>
  
  <p>EDIT: I ended up using <a href="http://codeigniter.com/wiki/PayPal_Lib" rel="nofollow">Ran Arrousi's Paypal lib for CodeIgniter</a> to build a form that can be submitted to paypal and then the same library to integrate PayPal IPN which checks if the payment was received.</p>