You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I am Mary Rodriguez. I want to book a flight ticket from SFO to PHX. Could you help me in booking?

ASSISTANT: Sure, please mention your travelling dates.

USER: My travelling dates are from April 25-27.

ASSISTANT: Please wait a moment.

USER: Ok.

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

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for reaching our service.