You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, may I know your planned travel dates?

USER: My travelling dates are Jan 12 and Jan 14.

ASSISTANT: Do you have any limits on number of connections?

USER: I need a direct flight.

ASSISTANT: Do you have any another specifications on your journey?

USER: I prefer business class.

ASSISTANT: May I know your name for the booking purpose?

USER: My name is John Walker.

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

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

ASSISTANT: Welcome, thank you for reaching us.