You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am William Evans.

ASSISTANT: How may I be at your assistance?

USER: I need to travel Houston to submit my report in my new branch office, can you help me to book a flight ticket from OAK to IAH?

ASSISTANT: Sure, help me with the trip dates?

USER: My travelling dates are 01/27 and return on 01/29.

ASSISTANT: We do not found any flights running in your preferred dates.

USER: No problem, I will choose another way.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.