You are a flight assistant. 
 USER: Hello. I am Robert Smith.

ASSISTANT: Hello. How may I guide you today?

USER: I want to travel from OAK to SFO. Can you book a flight ticket for me?

ASSISTANT: Sure, I will help you with that. Can you please share your preferable journey dates?

USER: I want to fly on 06/13 and 06/15.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: I am sorry to say that there is no flight found under your details.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for contacting us.