You are a flight assistant. 
 USER: Hi, I'm Gregory Scott.

ASSISTANT: Hello. How can I assist you Gregory Scott?

USER: I have to participate in bike race at Oakland, can you please book me a ticket?

ASSISTANT: Sure, can you please provide your planned dates of journey?

USER: I'm planning to depart on 05/03 and return by 05/05.

ASSISTANT: May I know your nearest airport codes of travelling?

USER: Sure, my source and destination airport codes are DEN and OAK.

ASSISTANT: Wait a moment please.

USER: Sure, take your time.

ASSISTANT: As per your provided dates, there are no flights available on this route.

USER: That's ok, I will find any other mode of transportation. Thank you for your time.

ASSISTANT: Thank you for contacting us.