You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Steven Harris.

ASSISTANT: Steven Harris. How can I help you?

USER: I am planning to visit San Francisco, will you help me in booking the flight ticket from ATL to SFO?

ASSISTANT: Sure, can you give me the trip dates?

USER: My preferable journey dates are Jan 18 and Jan 20.

ASSISTANT: Is there any airline preference?

USER: I am comfortable in any airlines.

ASSISTANT: May I know the class preference?

USER: I always prefer economy class.

ASSISTANT: Is there any time concern?

USER: My return time must be in evening.

ASSISTANT: Are there any other requirements?

USER: I need a flight with single connection.

ASSISTANT: Give me a moment?

USER: Ok, take your own time.

ASSISTANT: I regret to inform that there is no availability of flights on your routes.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for approaching us.