PayPalController.php

<?php 
	// etc...
	
	// find the payment if it already exists
	$payment = Payment::where('txn_id', '=', Input::get('txn_id'))->get()->first();
		
	// if it doesn't exist, create the payment using all the fields in the POST
	if (empty($payment)) $payment = Payment::create(Input::all());
    
	// if in debug mode, add the raw body of the request and also save it
	if (Config::get('app.debug')) {
		$payment->raw_request = print_r(Input::all(), true);
		$payment->save();
	}
		
	// etc...