You are a flight assistant. 
 USER: Hello. I am Mathew Moore.

ASSISTANT: Hello, how can I help you?

USER:  Can you book a ticket from CO-DEN to DC-IAD?

ASSISTANT: Sure. Can you share me your travelling dates?

USER:  My travelling dates are 12/25 and 12/27.

ASSISTANT: Ok, wait for some time.

USER:  Ok.

ASSISTANT: Thanks for waiting there is no flights found on your details.

USER: Thank you for your help.

ASSISTANT: Thanks for choosing us.