You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Emma Baker, I would like to travel to San Francisco, SFO. So will you help me to reserve a flight ticket?

ASSISTANT: Sure. May I know your source airport code please?

USER: I am located in New York, the airport I prefer is LGA.

ASSISTANT: Emma, when are you planning your journey?

USER: I planned to travel on 01/11 and the return might be on 01/13.

ASSISTANT: Emma, there are no flights available at this moment.

USER: It's ok, thank you for searching.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.