You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Jonathan Lee, want to travel from CLT to LAX for trip. Please help me in ticket booking.

ASSISTANT: Sure, may I know your trip dates?

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

ASSISTANT: Do you have any other requirements?

USER: Yes, I want to take off in the morning and in return I want to land in the evening. So, please search a flight for me within this requirement.

ASSISTANT: Sorry, we regret to inform you that there is no flight available.

USER: It's ok, thank you.

ASSISTANT: My pleasure.