You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Helen Carter.

ASSISTANT: Welcome to airline agency, how can I assist you today?

USER: I am planning to visit Denver Botanic Gardens  and most popular places in Denver, can you please help me out in booking?

ASSISTANT: Sure, I will definitely help you with that. Can you please help me by providing your travelling dates please?

USER: I am preferring to travel on my comfortable dates that are 05/13 and  05/15.

ASSISTANT: For booking the flight ticket, your airport codes are needed. Will you provide your airport codes that you want to travel?

USER: I would like to prefer my departure and arrival airport codes that are nearer to me they are SFO and DEN.

ASSISTANT: Please give me a moment.

USER: Sure, you can take your time.

ASSISTANT: Thank you for waiting.

USER: My pleasure.

ASSISTANT: There is no flights found under your preferable journey details.

USER: Anyway, thank you for your information.

ASSISTANT: Welcome, have a great day.