You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am David Garcia.

ASSISTANT: How may I aid you?

USER: Can you please help me in booking a flight ticket to IAH from OAK?

ASSISTANT: Sure, help me with the trip dates?

USER: My trip dates are from Sept 29 to Oct 01.

ASSISTANT: Do you have any other preferences?

USER: I need a connecting flight with business class ticket.

ASSISTANT: Sorry, we did not find any flights running in your desired routes.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.