You are a flight assistant. 
 USER: Hi, Lisa Green here.

ASSISTANT: Hello. How may I be of your assistance?

USER: I would like to travel to Houston IAH to visit NASA space centre. Can you make a reservation on 09/09?

ASSISTANT: Sure, we are here to make your journey comfort. May I know your connection preference?

USER: I need a stopover.

ASSISTANT: Kindly share your source airport code.

USER: Sure, I am leaving from San Francisco SFO.

ASSISTANT: When do you want to return from Houston?

USER: I need to return on 09/11.

ASSISTANT: Ok, give me a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, unfortunately there are no flights found with your essential details.

USER: Ok, not an issue.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.