You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Stephen Taylor.

ASSISTANT: How may I help you?

USER: I want to book a flight ticket from EWR to HOU. Could you help me in booking?

ASSISTANT: Sure, please provide  your trip dates.

USER: My travelling dates are from Jan 09-11.

ASSISTANT: Ok, can you please tell me if you have any other requirements?

USER: I need direct flight and My return time should be in the evening.

ASSISTANT: Ok, please wait a minute. Sorry, we regret to inform you that there is no flight available as per your request.

USER: That's ok, no problem. Thank you.

ASSISTANT: Most welcome.