You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I am John Anderson here, I want to reserve my ticket from IAD to LAX, can you please help me?

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: Thank you.

ASSISTANT: I am sorry. Please let me know with your planned travelling dates.

USER: Sure, my planned dates of journey are from May, 17 to May, 19.

ASSISTANT:  Do you need a direct or connecting flight?

USER: Yes, I need a direct flight.

ASSISTANT: Please help me with your preferred class to fly.

USER: I am ok with any class preference.

ASSISTANT: Do you have any other preferences in your journey?

USER: No.

ASSISTANT: John Anderson, I am really sorry to say that there are no flights available for your journey.

USER: Ok, no problem.

ASSISTANT: Thank you for understanding.

USER: Anyways, thank you for your service.

ASSISTANT: Thank you for reaching us. Have a great time.