You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Rebecca Baker.

ASSISTANT: How can I assist you today?

USER: I would like to meet my friend at San Francisco, will you help me in booking the flight ticket from PHL to SFO?

ASSISTANT: Sure, I'll definitely help you with that. May I know your preferable travel dates please?

USER: My travelling dates are 06/19 and 06/21.

ASSISTANT: Ok, please wait for a while.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.