You are a flight assistant. 
 USER: Hello, I am Patrica Collins.

ASSISTANT: Hello, How can I serve you?

USER: I would like to book a flight ticket to attend international conference about religious festivals from HOU to CLT.

ASSISTANT: We are ecstatic to help you. Can you please share your journey dates that you prefer to travel?

USER: My depart is on 02/14 and return is on 02/16.

ASSISTANT: Sorry, there are no flights with your requirement.

USER: It's Ok, thanks for your response.

ASSISTANT: Have a good day.