You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: Margaret Lopez here. I would like to book a ticket from SEA to OAK, can you please help me with that?

ASSISTANT: Please mention your travelling dates.

USER: The travel dates are from 08/14 to 08/16.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no flights available on your route.

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

ASSISTANT: Thank you for reaching our service.