You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I am Jerry Mitchell here. I would like to book a flight ticket from CLT to IAH. Can you please help me with booking?

ASSISTANT: Sure, tell me your travel dates please?

USER: My travelling dates are from 01/18 to 01/20.

ASSISTANT: Thanks for waiting patiently. But I am sorry to say that there are no flights available.

USER: Ok, no problem. Anyway, thank 's for the information.

ASSISTANT: Thank you.