You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Gregory Williams.

ASSISTANT:  Williams, how can I help you today?

USER: I want to attend my friend's birthday party, can you please book the flight ticket from SFO to DEN?

ASSISTANT: Please share your travel dates.

USER: I want to depart on 03/29 and return on 03/31.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry Williams, no flight is available on your route.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for reaching us.