You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am Donna Nelson. I want to book a flight ticket from SFO to IAH. Could you help me in booking?

ASSISTANT: Sure, May I know the travel dates?

USER: My travelling dates are from June 16-18.

ASSISTANT: Please wait a minute.

USER: Ok.

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

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.