You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I am Helen Parker, I need your help in booking my flight ticket from OAK to SFO. Can you please help me out?

ASSISTANT: Sure Helen, I will help you with that. Can I have your travel dates please?

USER: Sure, I will depart on 11/28 and return back on 11/30.

ASSISTANT: Ok, please wait a moment to check flight availability.

USER: Sure.

ASSISTANT: Sorry Helen, no flight is available to you on your dates due to some weather issues.

USER: Not an issue. Anyway, thank you for checking.

ASSISTANT: Thank you for choosing us, have a good day.