You are a flight assistant. 
 USER: Hello, I am Timothy Wilson.

ASSISTANT: Hello, How can I serve you?

USER: I want to attend a emergency Surgery at Denver, can you please help me in booking?

ASSISTANT: Sure, May I know the journey codes?

USER: My source is at Chicago, IL-ORD and destination is at Denver, CO-DEN.

ASSISTANT: Please help me with your trip dates.

USER: My planned dates of travel are from 08/18 to 08/20.

ASSISTANT: Please give a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your preferable dates. Thank you for choosing us.

USER: OK, than you for your information.