You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Benjamin Miller here.

ASSISTANT: How can I assist you Benjamin Miller?

USER: I am planing to take a flight on 05/07 and returning on 05/09. Can you reserve a seat for me?

ASSISTANT: Sure, I'll help you with this. Can you please share your airport codes of travelling?

USER: My airport codes are from AUS to OAK.

ASSISTANT: Wait for a moment please, let me check the best services on this route.

USER: Sure.

ASSISTANT: Sorry to inform you, there are no flights available on this route due to heavy bookings.

USER: It's ok, no issues.

ASSISTANT: Sorry for the inconvenience.

USER: Thank you for your information.

ASSISTANT: Thank you for contacting us.

USER: Welcome.