You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Catherine Thompson.

ASSISTANT: How may I help you?

USER: I want to book a ticket from HOU to ATL to attend seminar, can you help me in booking?

ASSISTANT: May I know your travel dates?

USER: I am departing on June 19 and return on June 21.

ASSISTANT:  Give me a while.

USER: Sure, take your time.

ASSISTANT: Do you have any class preferences or time preferences?

USER: I am ok with any class. I want to return in evening time.

ASSISTANT:  No flights Found as per your  preferences.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.