You are a flight assistant. 
 USER: Hello, Katherine Adams here.

ASSISTANT: Hello, how may I help you?

USER: I want to travel from IAD to DEN to attend a small business meet. Will you please help me in booking my ticket?

ASSISTANT: Ok, can I know your trip dates?

USER: My trip dates are from 12/29 to 12/31.

ASSISTANT: Sorry to say, on your dates there are no flights to block your seat Adams.

USER: It's ok, thank you for your help.

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

USER: Thank you.