diff --git a/php/EpiOAuth.php b/php/EpiOAuth.php
index 0d2771c..86fd329 100644
--- a/php/EpiOAuth.php
+++ b/php/EpiOAuth.php
@@ -5,6 +5,7 @@ class EpiOAuth
 
   protected $requestTokenUrl;
   protected $accessTokenUrl;
+  protected $authenticateUrl;
   protected $authorizeUrl;
   protected $consumerKey;
   protected $consumerSecret;
@@ -18,10 +19,14 @@ public function getAccessToken()
     return new EpiOAuthResponse($resp);
   }
 
-  public function getAuthorizationUrl()
+  public function getAuthenticateUrl()
   { 
-    $retval = "{$this->authorizeUrl}?";
+    $token = $this->getRequestToken();
+    return $this->authenticateUrl . '?oauth_token=' . $token->oauth_token;
+  }
 
+  public function getAuthorizationUrl()
+  { 
     $token = $this->getRequestToken();
     return $this->authorizeUrl . '?oauth_token=' . $token->oauth_token;
   }
@@ -219,8 +224,8 @@ public function __construct($resp)
 
   public function __get($name)
   {
-    if($this->__resp->code < 200 || $this->__resp->code > 299)
-      return false;
+    if($this->__resp->code != 200)
+      EpiOAuthException::raise($this->__resp->data, $this->__resp->code);
 
     parse_str($this->__resp->data, $result);
     foreach($result as $k => $v)
@@ -231,3 +236,23 @@ public function __get($name)
     return $result[$name];
   }
 }
+
+class EpiOAuthException extends Exception
+{
+  public static function raise($message, $code)
+  {
+    switch($code)
+    {
+      case 400:
+        throw new EpiOAuthBadRequestException($message, $code);
+      case 401:
+        throw new EpiOAuthUnauthorizedException($message, $code);
+      default:
+        throw new EpiOAuthException($message, $code);
+    }
+  }
+}
+
+
+class EpiOAuthBadRequestException extends EpiOAuthException{}
+class EpiOAuthUnauthorizedException extends EpiOAuthException{}
diff --git a/php/EpiTwitter.php b/php/EpiTwitter.php
index b0dac9f..ef7669f 100644
--- a/php/EpiTwitter.php
+++ b/php/EpiTwitter.php
@@ -15,6 +15,7 @@ class EpiTwitter extends EpiOAuth
   protected $requestTokenUrl= 'http://twitter.com/oauth/request_token';
   protected $accessTokenUrl = 'http://twitter.com/oauth/access_token';
   protected $authorizeUrl   = 'http://twitter.com/oauth/authorize';
+  protected $authenticateUrl= 'http://twitter.com/oauth/authenticate';
   protected $apiUrl         = 'http://twitter.com';
   protected $searchUrl      = 'http://search.twitter.com';
 
@@ -59,13 +60,13 @@ public function __construct($response)
   // Implementation of the IteratorAggregate::getIterator() to support foreach ($this as $...)
   public function getIterator ()
   {
-    return new ArrayIterator($this->response);
+    return new ArrayIterator($this->__obj);
   }
 
   // Implementation of Countable::count() to support count($this)
   public function count ()
   {
-    return count($this->response);
+    return count($this->__obj);
   }
   
   // Next four functions are to support ArrayAccess interface
@@ -95,10 +96,13 @@ public function offsetGet($offset)
 
   public function __get($name)
   {
+    if($this->__resp->code != 200)
+      EpiOAuthException::raise($this->__resp->data, $this->__resp->code);
+
     $this->responseText = $this->__resp->data;
     $this->response     = json_decode($this->responseText, 1);
-    $obj                = json_decode($this->responseText);
-    foreach($obj as $k => $v)
+    $this->__obj        = json_decode($this->responseText);
+    foreach($this->__obj as $k => $v)
     {
       $this->$k = $v;
     }
diff --git a/php/tests/EpiTwitterTest.php b/php/tests/EpiTwitterTest.php
index 24aeb61..d739c00 100644
--- a/php/tests/EpiTwitterTest.php
+++ b/php/tests/EpiTwitterTest.php
@@ -67,9 +67,12 @@ function testDirectMessage()
     $this->assertTrue(!empty($resp->response['id']), "response id is empty");
   }
 
+  /**
+  * @expectedException EpiOAuthException
+  */
   function testNoRequiredParameter()
   {
-    $resp = $this->twitterObj->post_direct_messagesNew( array ( 'user' => $this->screenName, 'text' => ""));
+    $resp = $this->twitterObj->post_direct_messagesNew( array ( 'user' => $this->screenName, 'text' => ''));
     $this->assertTrue(!empty($resp->response['error']), "An empty direct message should return an error message");
 
   }