You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Elizabeth Carter here. I want to take part in Boston marathon. Please book a ticket for me from LAX to BOS.

ASSISTANT: Sure, could you please provide your dates of travel to search for the flight?

USER: My journey dates are 06/20 and 06/22.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say, no flights were available on your dates.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.