You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: James Lee here.

ASSISTANT: Welcome to flight booking agency James.

USER: Please reserve me a ticket from SFO to ATL.

ASSISTANT: Sure, I am glad to help you with that.

USER: My trip dates are 05/21 and 05/23.

ASSISTANT: Can you please provide your planned dates of travelling?

USER: With the above mentioned dates please book a ticket.

ASSISTANT: Ok, please be on hold to check the flights availability on your route.

USER: Sure.

ASSISTANT: We regret to inform you that there are no flights moving to your region with your planned dates of travelling.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching to our services, hope you have a great day.