You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to fly to New York with the direct flight to visit Independence Hall, can you help me in booking?

ASSISTANT: Sure, please provide your travel dates.

USER: I am planning to travel on July 13 to July 15.

ASSISTANT: May I know your  airport codes?

USER: My boarding and landing airport codes are OAK and JFK.

ASSISTANT: Do you have any preferences?

USER: I prefer economy class ticket.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: May I know your name?

USER: I am William Campbell.

ASSISTANT: Sorry, I did not find any flights for you.

USER: No issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.