You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Rachel Edwards.

ASSISTANT: How may I guide you?

USER: I would like to visit Oakland for my friend's birthday, so I want to travel from 11/06 to 11/08.

ASSISTANT: Ok Rachel, please provide the airport codes?

USER: Ok, my source code is SEA and the destination code is OAK.

ASSISTANT: Ok, please give me a minute and I will check the availability of flights for you.

USER: Sure, take your time.

ASSISTANT: Sorry, there are no flights found which matches with your requirements.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you, have a great day.