You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Kevin Nelson. Can you help me in booking the ticket from LAS to IAD?

ASSISTANT: Sure, can you please let me know your travel dates?

USER: My planning dates are from 06/22 to 06/24.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Nelson, there are no flights available on your given dates.

USER: That's ok. Thank you.

ASSISTANT: You are welcome and thank you very much for choosing us.