You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I am Patrick Jones. I want to book a ticket from DFW to SFO, can you help me?

ASSISTANT: Ok, may I know your planned dates?

USER: My travel dates are Feb 19 and 21.

ASSISTANT: Do you have any class preference?

USER: I want to travel in economy class.

ASSISTANT: Ok, May I know your depart and arrival timings?

USER: I want to return in the morning.

ASSISTANT: Do you require any stopover in between your journey?

USER: I want a direct flight in my journey.

ASSISTANT: Ok, please give a minute of tome to check it.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no flight found with your requirements.

USER: No problem, thanks for checking.

ASSISTANT: Thank you.