diff --git a/README.md b/README.md
index 46190c0..8118a85 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,9 @@ This wrapper allows you to perform some basic calls to the USPS api. Some of the
 - Service Delivery Calculator
 - Confirm Tracking
 
+Be sure to read through the USPS develeloper documentation first!
+* https://www.usps.com/business/web-tools-apis/general-api-developer-guide.htm
+
 
 Requirements
 ============
@@ -26,6 +29,18 @@ Examples
 =======
 
 Please check the 'demos' directory for usage examples on the various types of api calls and actions you can perform.
+To run the demos you'll need to refresh Composer autoloading:
+```
+wget https://getcomposer.org/composer.phar
+php composer.phar dump-autoload
+```
+
+To run via the built-in PHP web server:
+* Run this command from the root directory of this project:
+```
+php -S localhost:8888
+```
+* From your browser: `http://localhost:8888`
 
 
 Authors
diff --git a/demos/address_verify.php b/demos/address_verify.php
index e40ebd9..08fcd0f 100644
--- a/demos/address_verify.php
+++ b/demos/address_verify.php
@@ -1,12 +1,16 @@
 <?php
+// USAGE: address_verify.php USPS_USER [USPS_PASSWORD]
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\{USPSAddress,USPSAddressVerify};
 
-// Load the class
-require_once('../USPSAddressVerify.php');
 // Initiate and set the username provided from usps
-$verify = new USPSAddressVerify('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$verify = new USPSAddressVerify($user, $pass);
 
 // During test mode this seems not to always work as expected
-//$verify->setTestMode(true);
+$verify->setTestMode(true);
 
 // Create new address object and assign the properties
 // apartently the order you assign them is important so make sure
diff --git a/demos/citystatelookup.php b/demos/citystatelookup.php
index 3cf178d..5f74b14 100644
--- a/demos/citystatelookup.php
+++ b/demos/citystatelookup.php
@@ -1,12 +1,16 @@
 <?php
-// Load the class
-require_once('../USPSCityStateLookup.php');
+// USAGE: citystatelookup.php USPS_USER [USPS_PASSWORD]
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSCityStateLookup;
 
 // Initiate and set the username provided from usps
-$verify = new USPSCityStateLookup('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$verify = new USPSCityStateLookup($user, $pass);
 
 // During test mode this seems not to always work as expected
-//$verify->setTestMode(true);
+$verify->setTestMode(true);
 
 // Add the zip code we want to lookup the city and state
 $verify->addZipCode('91730');
diff --git a/demos/domestic_rate.php b/demos/domestic_rate.php
index 288bdfc..07002a8 100644
--- a/demos/domestic_rate.php
+++ b/demos/domestic_rate.php
@@ -1,12 +1,16 @@
 <?php
-// Load the class
-require_once('../USPSRate.php');
+// USAGE: domestic_rate.php USPS_USER [USPS_PASSWORD]
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\{USPSRate,USPSRatePackage};
 
 // Initiate and set the username provided from usps
-$rate = new USPSRate('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$rate = new USPSRate($user, $pass);
 
 // During test mode this seems not to always work as expected
-//$rate->setTestMode(true);
+$rate->setTestMode(true);
 
 // Create new package object and assign the properties
 // apartently the order you assign them is important so make sure
diff --git a/demos/firstclassservicestandard.php b/demos/firstclassservicestandard.php
index c8fd590..887532e 100644
--- a/demos/firstclassservicestandard.php
+++ b/demos/firstclassservicestandard.php
@@ -1,9 +1,12 @@
 <?php
-// Load the class
-require_once('../USPSFirstClassServiceStandards.php');
+// USAGE: firstclassservicestandard.php USPS_USER
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSFirstClassServiceStandards;
 
 // Initiate and set the username provided from usps.
-$delivery = new USPSFirstClassServiceStandards('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$delivery = new USPSFirstClassServiceStandards($user);
 
 // During test mode this seems not to always work as expected.
 $delivery->setTestMode(true);
diff --git a/demos/international_express_label.php b/demos/international_express_label.php
index f391f3e..af6197c 100644
--- a/demos/international_express_label.php
+++ b/demos/international_express_label.php
@@ -1,18 +1,18 @@
 <?php
+// USAGE: international_express_label.php USPS_USER USPS_PASSWORD ExpressMailIntl|PriorityMailIntl|FirstClassMailIntl
+// NOTE: APIs that return printed labels or barcodes become available after applying for advanced permissions from the USPS APIs Functional Team.
+//       Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSInternationalLabel;
 
-// Load the class
-require_once('../USPSInternationalLabel.php');
 // Initiate and set the username provided from usps
-$label = new USPSInternationalLabel('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$version = $argv[3] ?? $_GET['version'] ?? 'ExpressMailIntl';
+$label = new USPSInternationalLabel($user, $pass);
 
 // Express by default
-$label->setApiVersion('ExpressMailIntl');
-
-// PriorityMailIntl
-$label->setApiVersion('PriorityMailIntl');
-
-// FirstClassMailIntl
-$label->setApiVersion('FirstClassMailIntl');
+$label->setApiVersion($version);
 
 // During test mode this seems not to always work as expected
 $label->setTestMode(true);
diff --git a/demos/open_label.php b/demos/open_label.php
index 577d8a0..f81f076 100644
--- a/demos/open_label.php
+++ b/demos/open_label.php
@@ -1,10 +1,17 @@
 <?php
+// USAGE: open_label.php USPS_USER USPS_PASSWORD
+// NOTE: APIs that return printed labels or barcodes become available after applying for advanced permissions from the USPS APIs Functional Team.
+//       Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSOpenDistributeLabel;
 
-// Load the class
-require_once('../USPSOpenDistributeLabel.php');
 // Initiate and set the username provided from usps
-$label = new USPSOpenDistributeLabel('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$label = new USPSOpenDistributeLabel($user, $pass);
 
+// During test mode this seems not to always work as expected
+$label->setTestMode(true);
 
 $label->setFromAddress('John', 'Doe', '', '5161 Lankershim Blvd', 'North Hollywood', 'CA', '91601', '# 204');
 $label->setToAddress('Vincent Gabriel', '5440 Tujunga Ave', 'North Hollywood', 'CA', '91601', '707');
diff --git a/demos/priority_label.php b/demos/priority_label.php
index f9686fc..012c3e5 100644
--- a/demos/priority_label.php
+++ b/demos/priority_label.php
@@ -1,9 +1,14 @@
 <?php
+// USAGE: priority_label.php USPS_USER USPS_PASSWORD
+// NOTE: APIs that return printed labels or barcodes become available after applying for advanced permissions from the USPS APIs Functional Team.
+//       Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSPriorityLabel;
 
-// Load the class
-require_once('../USPSPriorityLabel.php');
 // Initiate and set the username provided from usps
-$label = new USPSPriorityLabel('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$label = new USPSPriorityLabel($user, $pass);
 
 // During test mode this seems not to always work as expected
 $label->setTestMode(true);
@@ -29,7 +34,7 @@
   //echo "\n Confirmation:" . $label->getConfirmationNumber();
 
   $label = $label->getLabelContents();
-  
+
   if($label) {
   	$contents = base64_decode($label);
   	header('Content-type: application/pdf');
diff --git a/demos/servicedeliverycalculator.php b/demos/servicedeliverycalculator.php
index 518e793..392a961 100644
--- a/demos/servicedeliverycalculator.php
+++ b/demos/servicedeliverycalculator.php
@@ -1,9 +1,13 @@
 <?php
-// Load the class
-require_once('../USPSServiceDeliveryCalculator.php');
+// USAGE: servicedeliverycalculator.php USPS_USER USPS_PASSWORD
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSServiceDeliveryCalculator;
 
 // Initiate and set the username provided from usps
-$delivery = new USPSServiceDeliveryCalculator('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$delivery = new USPSServiceDeliveryCalculator($user, $pass);
 
 // During test mode this seems not to always work as expected
 $delivery->setTestMode(true);
diff --git a/demos/trackconfirm.php b/demos/trackconfirm.php
index 327c6ac..a2a6239 100644
--- a/demos/trackconfirm.php
+++ b/demos/trackconfirm.php
@@ -1,9 +1,13 @@
 <?php
-// Load the class
-require_once('../USPSTrackConfirm.php');
+// USAGE: trackconfirm.php USPS_USER USPS_PASSWORD
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\USPSTrackConfirm;
 
 // Initiate and set the username provided from usps
-$tracking = new USPSTrackConfirm('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$tracking = new USPSTrackConfirm($user, $pass);
 
 // During test mode this seems not to always work as expected
 $tracking->setTestMode(true);
@@ -22,4 +26,4 @@
   echo 'Error: ' . $tracking->getErrorMessage();
 }
 
-?>
\ No newline at end of file
+?>
diff --git a/demos/zipcodelookup.php b/demos/zipcodelookup.php
index f3301cc..57d0c62 100644
--- a/demos/zipcodelookup.php
+++ b/demos/zipcodelookup.php
@@ -1,12 +1,16 @@
 <?php
-// Load the class
-require_once('../USPSZipCodeLookup.php');
+// USAGE: zipcodelookup.php USPS_USER [USPS_PASSWORD]
+// NOTE:  Be sure to run composer dump-autoload to update autoload file mapping
+require __DIR__ . '/../vendor/autoload.php';
+use USPS\{USPSZipCodeLookup,USPSAddress};
 
 // Initiate and set the username provided from usps
-$zipcode = new USPSZipCodeLookup('xxxx');
+$user   = $argv[1] ?? $_GET['user'] ?? 'xxx';
+$pass   = $argv[2] ?? $_GET['password'] ?? '';
+$zipcode = new USPSZipCodeLookup($user, $pass);
 
 // During test mode this seems not to always work as expected
-//$verify->setTestMode(true);
+$zipcode->setTestMode(true);
 
 // Create new address object and assign the properties
 // apartently the order you assign them is important so make sure
diff --git a/index.php b/index.php
new file mode 100644
index 0000000..f9de65c
--- /dev/null
+++ b/index.php
@@ -0,0 +1,40 @@
+<?php
+// use this to run the demo programs via the built-in PHP web server
+// to run, from the project root run this command:
+// php -S localhost:8888
+// then, from your browser: http://localhost:8888
+session_start();
+if (!empty($_GET)) {
+    $user = (!empty($_GET['user'])) ? strip_tags($_GET['user']) : '';
+    $password = (!empty($_GET['password'])) ? strip_tags($_GET['password']) : '';
+    $_SESSION['user'] = $user;
+    $_SESSION['password'] = $password;
+}
+$user = $_SESSION['user'] ?? '';
+$password = $_SESSION['password'] ?? '';
+$html = '<ul>';
+$list = new RecursiveDirectoryIterator(__DIR__ . '/demos');
+foreach ($list as $name => $obj) {
+    $html .= ($obj->isFile())
+             ? '<li><a target="_blank" href="/demos/' . basename($name) . '?user=' . $user . '&password=' . $password . '">' . basename($name) . '</a></li>'
+             : '';
+}
+$html .= '</ul>';
+?>
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8" />
+<title>USPS PHP API Test</title>
+<meta name="generator" content="Geany 1.38" />
+</head>
+<body>
+<form method="get">
+USPS Username: <input type="text" name="user" value="<?= htmlspecialchars($user); ?>" />&nbsp;
+USPS Password: <input type="text" name="password" value="<?= htmlspecialchars($password); ?>" />&nbsp;
+<input type="submit" name="submit" value="Update" />
+</form>
+<?= $html; ?>
+</body>
+</html>
+
diff --git a/src/USPS/USPSBase.php b/src/USPS/USPSBase.php
index 9bfd323..133b6d4 100644
--- a/src/USPS/USPSBase.php
+++ b/src/USPS/USPSBase.php
@@ -11,13 +11,17 @@
  * @author Vincent Gabriel
  */
 class USPSBase {
-  const LIVE_API_URL = 'http://production.shippingapis.com/ShippingAPI.dll';
-  const TEST_API_URL = 'http://production.shippingapis.com/ShippingAPITest.dll';
+  const LIVE_API_URL = 'https://stg-secure.shippingapis.com/shippingapi.dll';
+  const TEST_API_URL = 'https://secure.shippingapis.com/shippingapi.dll';
 
   /**
    * @var string - the usps username provided by the usps website
    */
   protected $username = '';
+  /**
+   * @var string - the usps password provided by the usps website
+   */
+  protected $password = '';
   /**
    *  the error code if one exists
    * @var integer
@@ -94,9 +98,11 @@ class USPSBase {
   /**
    * Constructor
    * @param string $username - the usps api username
+   * @param string $password - the usps api password
    */
-  public function __construct($username='') {
+  public function __construct($username='', $password='') {
     $this->username = $username;
+    $this->password = $password;
   }
   /**
    * set the usps api username we are going to user
@@ -201,10 +207,15 @@ public function getEndpoint() {
    */
   protected function getXMLString() {
     // Add in the defaults
-    $postFields = array(
-      '@attributes' => array('USERID' => $this->username),
-    );
-
+    if (!empty($this->password)) {
+        $postFields = array(
+          '@attributes' => array('USERID' => $this->username, 'PASSWORD' => $this->password),
+        );
+    } else {
+        $postFields = array(
+          '@attributes' => array('USERID' => $this->username),
+        );
+    }
     // Add in the sub class data
     $postFields = array_merge($postFields, $this->getPostFields());
 
diff --git a/src/USPS/USPSRate.php b/src/USPS/USPSRate.php
index d6bd432..a9cf60e 100644
--- a/src/USPS/USPSRate.php
+++ b/src/USPS/USPSRate.php
@@ -59,149 +59,3 @@ public function addPackage(USPSRatePackage $data, $id=null) {
     $this->packages['Package'][] = array_merge(array('@attributes' => array('ID' => $packageId)), $data->getPackageInfo());
   }
 }
-/**
- * USPS Rate Package
- * used by the ups rate class to create packages represented as objects
- * @since 1.0
- * @author Vincent Gabriel
- */
-class USPSRatePackage extends USPSRate {
-  /**
-   * @var array - list of all packages added so far
-   */
-  protected $packageInfo = array();
-  /**
-   * Services constants
-   */
-  const SERVICE_FIRST_CLASS = 'FIRST CLASS';
-  const SERVICE_FIRST_CLASS_COMMERCIAL = 'FIRST CLASS COMMERCIAL';
-  const SERVICE_FIRST_CLASS_HFP_COMMERCIAL = 'FIRST CLASS HFP COMMERCIAL';
-  const SERVICE_PRIORITY = 'PRIORITY';
-  const SERVICE_PRIORITY_COMMERCIAL = 'PRIORITY COMMERCIAL';
-  const SERVICE_PRIORITY_HFP_COMMERCIAL = 'PRIORITY HFP COMMERCIAL';
-  const SERVICE_EXPRESS = 'EXPRESS';
-  const SERVICE_EXPRESS_COMMERCIAL = 'EXPRESS COMMERCIAL';
-  const SERVICE_EXPRESS_SH = 'EXPRESS SH';
-  const SERVICE_EXPRESS_SH_COMMERCIAL = 'EXPRESS SH COMMERCIAL';
-  const SERVICE_EXPRESS_HFP = 'EXPRESS HFP';
-  const SERVICE_EXPRESS_HFP_COMMERCIAL = 'EXPRESS HFP COMMERCIAL';
-  const SERVICE_PARCEL = 'PARCEL';
-  const SERVICE_MEDIA = 'MEDIA';
-  const SERVICE_LIBRARY = 'LIBRARY';
-  const SERVICE_ALL = 'ALL';
-  const SERVICE_ONLINE = 'ONLINE';
-  /**
-   * First class mail type
-   * required when you use one of the first class services
-   */
-  const MAIL_TYPE_LETTER = 'LETTER';
-  const MAIL_TYPE_FLAT = 'FLAT';
-  const MAIL_TYPE_PARCEL = 'PARCEL';
-  const MAIL_TYPE_POSTCARD = 'POSTCARD';
-  const MAIL_TYPE_PACKAGE_SERVICE = 'PACKAGE SERVICE';
-  /**
-   * Container constants
-   */
-  const CONTAINER_VARIABLE = 'VARIABLE';
-  const CONTAINER_FLAT_RATE_ENVELOPE = 'FLAT RATE ENVELOPE';
-  const CONTAINER_PADDED_FLAT_RATE_ENVELOPE = 'PADDED FLAT RATE ENVELOPE';
-  const CONTAINER_LEGAL_FLAT_RATE_ENVELOPE = 'LEGAL FLAT RATE ENVELOPE';
-  const CONTAINER_SM_FLAT_RATE_ENVELOPE = 'SM FLAT RATE ENVELOPE';
-  const CONTAINER_WINDOW_FLAT_RATE_ENVELOPE = 'WINDOW FLAT RATE ENVELOPE';
-  const CONTAINER_GIFT_CARD_FLAT_RATE_ENVELOPE = 'GIFT CARD FLAT RATE ENVELOPE';
-  const CONTAINER_FLAT_RATE_BOX = 'FLAT RATE BOX';
-  const CONTAINER_SM_FLAT_RATE_BOX = 'SM FLAT RATE BOX';
-  const CONTAINER_MD_FLAT_RATE_BOX = 'MD FLAT RATE BOX';
-  const CONTAINER_LG_FLAT_RATE_BOX = 'LG FLAT RATE BOX';
-  const CONTAINER_REGIONALRATEBOXA = 'REGIONALRATEBOXA';
-  const CONTAINER_REGIONALRATEBOXB = 'REGIONALRATEBOXB';
-  const CONTAINER_REGIONALRATEBOXC = 'REGIONALRATEBOXC';
-  const CONTAINER_RECTANGULAR = 'RECTANGULAR';
-  const CONTAINER_NONRECTANGULAR = 'NONRECTANGULAR';
-  /**
-   * Size constants
-   */
-  const SIZE_LARGE = 'LARGE';
-  const SIZE_REGULAR = 'REGULAR';
-  /**
-   * Set the service property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setService($value) {
-    return $this->setField('Service', $value);
-  }
-  /**
-   * Set the first class mail type property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setFirstClassMailType($value) {
-    return $this->setField('FirstClassMailType', $value);
-  }
-  /**
-   * Set the zip origin property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setZipOrigination($value) {
-    return $this->setField('ZipOrigination', $value);
-  }
-  /**
-   * Set the zip destination property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setZipDestination($value) {
-    return $this->setField('ZipDestination', $value);
-  }
-  /**
-   * Set the pounds property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setPounds($value) {
-    return $this->setField('Pounds', $value);
-  }
-  /**
-   * Set the ounces property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setOunces($value) {
-    return $this->setField('Ounces', $value);
-  }
-  /**
-   * Set the container property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setContainer($value) {
-    return $this->setField('Container', $value);
-  }
-  /**
-   * Set the size property
-   * @param string|int $value
-   * @return object USPSRatePackage
-   */
-  public function setSize($value) {
-    return $this->setField('Size', $value);
-  }
-  /**
-   * Add an element to the stack
-   * @param string|int $key
-   * @param string|int $value
-   * @return object USPSAddress
-   */
-  public function setField($key, $value) {
-    $this->packageInfo[ ucwords($key) ] = $value;
-    return $this;
-  }
-  /**
-   * Returns a list of all the info we gathered so far in the current package object
-   * @return array
-   */
-  public function getPackageInfo() {
-    return $this->packageInfo;
-  }
-}
diff --git a/src/USPS/USPSRatePackage.php b/src/USPS/USPSRatePackage.php
new file mode 100644
index 0000000..d1bad1c
--- /dev/null
+++ b/src/USPS/USPSRatePackage.php
@@ -0,0 +1,149 @@
+<?php
+namespace USPS;
+
+/**
+ * USPS Rate Package
+ * used by the ups rate class to create packages represented as objects
+ * @since 1.0
+ * @author Vincent Gabriel
+ */
+class USPSRatePackage extends USPSRate {
+  /**
+   * @var array - list of all packages added so far
+   */
+  protected $packageInfo = array();
+  /**
+   * Services constants
+   */
+  const SERVICE_FIRST_CLASS = 'FIRST CLASS';
+  const SERVICE_FIRST_CLASS_COMMERCIAL = 'FIRST CLASS COMMERCIAL';
+  const SERVICE_FIRST_CLASS_HFP_COMMERCIAL = 'FIRST CLASS HFP COMMERCIAL';
+  const SERVICE_PRIORITY = 'PRIORITY';
+  const SERVICE_PRIORITY_COMMERCIAL = 'PRIORITY COMMERCIAL';
+  const SERVICE_PRIORITY_HFP_COMMERCIAL = 'PRIORITY HFP COMMERCIAL';
+  const SERVICE_EXPRESS = 'EXPRESS';
+  const SERVICE_EXPRESS_COMMERCIAL = 'EXPRESS COMMERCIAL';
+  const SERVICE_EXPRESS_SH = 'EXPRESS SH';
+  const SERVICE_EXPRESS_SH_COMMERCIAL = 'EXPRESS SH COMMERCIAL';
+  const SERVICE_EXPRESS_HFP = 'EXPRESS HFP';
+  const SERVICE_EXPRESS_HFP_COMMERCIAL = 'EXPRESS HFP COMMERCIAL';
+  const SERVICE_PARCEL = 'PARCEL';
+  const SERVICE_MEDIA = 'MEDIA';
+  const SERVICE_LIBRARY = 'LIBRARY';
+  const SERVICE_ALL = 'ALL';
+  const SERVICE_ONLINE = 'ONLINE';
+  /**
+   * First class mail type
+   * required when you use one of the first class services
+   */
+  const MAIL_TYPE_LETTER = 'LETTER';
+  const MAIL_TYPE_FLAT = 'FLAT';
+  const MAIL_TYPE_PARCEL = 'PARCEL';
+  const MAIL_TYPE_POSTCARD = 'POSTCARD';
+  const MAIL_TYPE_PACKAGE_SERVICE = 'PACKAGE SERVICE';
+  /**
+   * Container constants
+   */
+  const CONTAINER_VARIABLE = 'VARIABLE';
+  const CONTAINER_FLAT_RATE_ENVELOPE = 'FLAT RATE ENVELOPE';
+  const CONTAINER_PADDED_FLAT_RATE_ENVELOPE = 'PADDED FLAT RATE ENVELOPE';
+  const CONTAINER_LEGAL_FLAT_RATE_ENVELOPE = 'LEGAL FLAT RATE ENVELOPE';
+  const CONTAINER_SM_FLAT_RATE_ENVELOPE = 'SM FLAT RATE ENVELOPE';
+  const CONTAINER_WINDOW_FLAT_RATE_ENVELOPE = 'WINDOW FLAT RATE ENVELOPE';
+  const CONTAINER_GIFT_CARD_FLAT_RATE_ENVELOPE = 'GIFT CARD FLAT RATE ENVELOPE';
+  const CONTAINER_FLAT_RATE_BOX = 'FLAT RATE BOX';
+  const CONTAINER_SM_FLAT_RATE_BOX = 'SM FLAT RATE BOX';
+  const CONTAINER_MD_FLAT_RATE_BOX = 'MD FLAT RATE BOX';
+  const CONTAINER_LG_FLAT_RATE_BOX = 'LG FLAT RATE BOX';
+  const CONTAINER_REGIONALRATEBOXA = 'REGIONALRATEBOXA';
+  const CONTAINER_REGIONALRATEBOXB = 'REGIONALRATEBOXB';
+  const CONTAINER_REGIONALRATEBOXC = 'REGIONALRATEBOXC';
+  const CONTAINER_RECTANGULAR = 'RECTANGULAR';
+  const CONTAINER_NONRECTANGULAR = 'NONRECTANGULAR';
+  /**
+   * Size constants
+   */
+  const SIZE_LARGE = 'LARGE';
+  const SIZE_REGULAR = 'REGULAR';
+  /**
+   * Set the service property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setService($value) {
+    return $this->setField('Service', $value);
+  }
+  /**
+   * Set the first class mail type property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setFirstClassMailType($value) {
+    return $this->setField('FirstClassMailType', $value);
+  }
+  /**
+   * Set the zip origin property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setZipOrigination($value) {
+    return $this->setField('ZipOrigination', $value);
+  }
+  /**
+   * Set the zip destination property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setZipDestination($value) {
+    return $this->setField('ZipDestination', $value);
+  }
+  /**
+   * Set the pounds property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setPounds($value) {
+    return $this->setField('Pounds', $value);
+  }
+  /**
+   * Set the ounces property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setOunces($value) {
+    return $this->setField('Ounces', $value);
+  }
+  /**
+   * Set the container property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setContainer($value) {
+    return $this->setField('Container', $value);
+  }
+  /**
+   * Set the size property
+   * @param string|int $value
+   * @return object USPSRatePackage
+   */
+  public function setSize($value) {
+    return $this->setField('Size', $value);
+  }
+  /**
+   * Add an element to the stack
+   * @param string|int $key
+   * @param string|int $value
+   * @return object USPSAddress
+   */
+  public function setField($key, $value) {
+    $this->packageInfo[ ucwords($key) ] = $value;
+    return $this;
+  }
+  /**
+   * Returns a list of all the info we gathered so far in the current package object
+   * @return array
+   */
+  public function getPackageInfo() {
+    return $this->packageInfo;
+  }
+}