ConvertCurrency.php

<?php
// Include required library files.
require_once('includes/config.php');
require_once('includes/paypal.class.php');

// Create PayPal object.
$PayPalConfig = array(
					  'Sandbox' => $sandbox,
					  'DeveloperAccountEmail' => $developer_account_email,
					  'ApplicationID' => $application_id,
					  'DeviceID' => $device_id,
					  'IPAddress' => $_SERVER['REMOTE_ADDR'],
					  'APIUsername' => $api_username,
					  'APIPassword' => $api_password,
					  'APISignature' => $api_signature,
					  'APISubject' => $api_subject
					);

$PayPal = new PayPal_Adaptive($PayPalConfig);

// Prepare request arrays
$BaseAmountList = array();
$BaseAmountData = array(
						'Code' => '', 						// Currency code.
						'Amount' => ''						// Amount to be converted.
						);
array_push($BaseAmountList, $BaseAmountData);

$ConvertToCurrencyList = array('USD', 'AUD', 'CAD');			// Currency Codes

$PayPalRequestData = array(
						'BaseAmountList' => $BaseAmountList, 
						'ConvertToCurrencyList' => $ConvertToCurrencyList
						);

// Pass data into class for processing with PayPal and load the response array into $PayPalResult
$PayPalResult = $PayPal->ConvertCurrency($PayPalRequestData);

// Write the contents of the response array to the screen for demo purposes.
echo '<pre />';
print_r($PayPalResult);
?>