You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to enjoy the winter at Chicago, please book a ticket ?

ASSISTANT: Sure, can you please provide me your travelling details?

USER: My source point is at San Francisco,CA-SFO, and destination airport code is IL-ORD. My travel dates are from 01/26 to 01/28.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Unfortunately, there were no flights on your preferred dates. May I know your name please?

USER: Ok, No issue. Sure, I am Karen Collins. Thank you for your assistance.

ASSISTANT: Thank you for connecting us, have a good day.