You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am David Perez.

ASSISTANT: How can I help you today?

USER: I am looking for a flight from OAK to LGA, can you please help me in booking?

ASSISTANT: Sure, I am here to help you in booking. Can I have your travel dates please?

USER: My travelling dates are Feb 06 and Feb 08.

ASSISTANT: Do you have any specifications?

USER: My return time is evening.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing.