You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: Myself Catherine Thomas, can you help me to book a flight ticket from CA - SFO to IL - ORD?

ASSISTANT: I understand your request and will be happy to help you.

USER: Thank you for helping me.

ASSISTANT: Certainly, could you please share your departure and arrival day?

USER: Yes, I will be starting on 02/17 and return date is 02/19.

ASSISTANT: Could you mind be on hold for a  while I am checking with your requested details?

USER: Ok, I will wait.

ASSISTANT: Sorry, all flights are busy on your requested travelling dates.

USER: That's ok, not a problem.

ASSISTANT: My pleasure. If any other questions arise, please feel free to contact us at any time.

USER: Thank you for your expeditious service.