 		
 		let request = self.requestWithEndPoint(.DeleteBookmark, pathComponents: [bookmarkID], method: .POST, parameters: nil)
 		self.sendAsynchronousRequest(request) { (response, error) -> Void in
-			if (response != nil && response == "OK") {
-				completion(success: true)
-			} else {
-				completion(success: false)
-			}
-		}
-	}
-	
-	/// Returns the exercise log of the user for a given bookmark.
+			self.checkBooleanResponse(response, error: error, completion: completion);
+		}
+	}
+	
+	/// Retrieves the exercise log of the user for a given bookmark.
 	///
 	/// - parameter bookmarkID: The ID of the bookmark for which to get the exercise log.
 	/// - parameter completion: A block that will receive a `JSON` object, which contains the exercise log.

		}
	}
	
	/// Returns the language codes of all available languages that the Zeeguu API supports.
	///
	/// - parameter completion: A block that will receive a `JSON` object, which contains the array with the language codes.
	public func getAvailableLanguages(completion: (array: JSON?) -> Void) {

		}
		let request = self.requestWithEndPoint(.LearnedLanguage, pathComponents: [newLanguageCode], method: .POST, parameters: nil)
		self.sendAsynchronousRequest(request) { (response, error) -> Void in
			self.checkBooleanResponse(response, error: error, completion: completion);
		}
	}
	
	/// Retrieves the language code of the native langugage of the logged in user.
	///
	/// - parameter completion: A block that will receive a language code of the native language or nil if the request couldn't be completed.
	public func getNativeLanguage(completion: (langCode: String?) -> Void) {
