You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: Myself Stephen Thompson from Chicago.

ASSISTANT: What can I do for you?

USER: I want to go to Houston next week for attending a birthday party there. Can you please book a flight ticket for me?

ASSISTANT: Ok, please tell me your travelling dates for this journey?

USER: Thank you, I want to take off on 07/28 and please confirm my return ticket also on 07/30.

ASSISTANT: Ok, may I know your arrival and departure airport codes respectively?

USER: I want to fly from ORD and destination airport is HOU.

ASSISTANT: Sorry, no flights are available as per your request.

USER: Oh! It's ok no problem.

ASSISTANT: Thank you for availing us.

USER: Thank you for your information.

ASSISTANT: Have a nice day.