/**
  * 
  */
 public static function hasApplicationID($dsn, $user, $object_type, $TxnID_or_ListID)
 {
     if (QuickBooks_Utilities::fetchApplicationID($dsn, $user, $object_type, $TxnID_or_ListID)) {
         return true;
     }
     return false;
 }
<?php

require_once '/home/library_php/QuickBooks.php';
$dsn = 'mysql://*****:*****@localhost/quickbooks';
$user = '******';
QuickBooks_Utilities::createMapping($dsn, $user, QUICKBOOKS_OBJECT_CUSTOMER, '1234-1234', 15);
print "\n";
print "\n";
print 'App ID: ' . QuickBooks_Utilities::fetchApplicationID($dsn, $user, QUICKBOOKS_OBJECT_CUSTOMER, '1234-1234');
print "\n";
print "\n";
print 'QB ID: ' . QuickBooks_Utilities::fetchQuickbooksID($dsn, $user, QUICKBOOKS_OBJECT_CUSTOMER, 15);
print "\n";
print "\n";