You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to book a ticket can you assist me please?

ASSISTANT: Sure, please give your source and destination airport codes.

USER: I want to book a ticket from NV - LAS to IL - ORD.

ASSISTANT: Will you provide your travelling dates?

USER: My journey dates are 09/02 & 09/04.

ASSISTANT: May I know your name?

USER: My name is Anthony Campbell.

ASSISTANT: Sorry to say that Anthony, unfortunately there is no flights found.

USER: OK. Thank you for your support.

ASSISTANT: Thanks for reaching us. Have a nice day.