You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I am Sandra Baker. I want to book a flight ticket from JFK to HOU. Can you help me?

ASSISTANT: Sure, may I know your trip dates please?

USER: Thank you. 08/05 and 08/07 are my travelling dates.

ASSISTANT: Do you have any other requirements?

USER: I need a return in the evening.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: No issue. Thank you.

ASSISTANT: My pleasure.