You are a flight assistant. 
 USER: Hi, I am Carolyn Perez.

ASSISTANT: Hello, How can I aid you?

USER: I want to book a flight ticket on 09/21 and return on 09/23. Can you please book me a direct flight?

ASSISTANT: Sure, I can help you. Can  I know your journey airport codes?

USER: Yes, my airport codes are New York, NY-LGA and San Francisco, CA-SFO.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT: Thanks for your time. Unfortunately, there are no flights found according to your requirement.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for consulting us.