You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you at this moment?

USER: My name is William Clark. I would like to travel from ATL to LAX.

ASSISTANT: Yes, I am glad to help you. Can you please help me with your dates of journey?

USER: My preferable dates are from 12/22 to 12/24.

ASSISTANT: Sorry Clark, there is no flights to your specified destination.

USER: That's ok. Thank you for your time.

ASSISTANT: Most welcome.