You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Matthew Perez. Can you please book a flight ticket from CLT to ORD?

ASSISTANT: Sure, on which dates you are planning to travel?

USER: Thank you. I have planned to travel on dates of July 28 and July 30.

ASSISTANT: Sorry, on these dates there is no flights available.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Most welcome.