You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Karen Robinson.

ASSISTANT: How may I aid you today?

USER: Can you please book a flight ticket from SFO to OAK?

ASSISTANT: Please mention your travelling dates.

USER: Sure, I need to travel on dates of 05/22 and 05/24.

ASSISTANT: Sorry Karen, there are no flights running on that route.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for choosing our service.

USER: Most welcome.