You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Jack Phillips, can you help me to book a flight from LAX to ORD?

ASSISTANT: Can you please tell your travelling dates?

USER: Ok, my travel departure date is 02/18 and return date is 02/20.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: That's ok, not a problem. Thank you for assisting me.

ASSISTANT: Thank you and have a nice day.