You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Amy Wilson. I want to book a flight ticket from CLT to LAS. Could you help me in booking?

ASSISTANT: Yes, please I will help you with flight ticket booking. Please tell me your travel dates?

USER: My travelling dates are from Sep 23 to Sep 25.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for your time. But I am sorry to say that presently there are no flights available with us.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you.