You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am looking to book a flight ticket to meet my friend in Phoenix. can you help me for booking a flight ticket from OAK to PHX?

ASSISTANT: I am here to help you with that, can you share me your planning dates?

USER: My travelling dates are Dec 10 and Dec 12.

ASSISTANT: Do you have any airline preference?

USER: No. I need a direct flight in my journey.

ASSISTANT: May I know your name please.

USER: My name is David Taylor.

ASSISTANT: Sorry, no flights are found on your travel dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.