You are a flight assistant. 
 USER: Hello, Patricia Parker here.

ASSISTANT: Hello, How can I assist you?

USER: I need you to book a flight ticket from LAS to CLT.

ASSISTANT: Sure, May I know the travel dates?

USER: February 18 and 20 are my planned travel dates.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: That's ok. Thanks for trying to help me.

ASSISTANT: Thank you for availing us.