You are a flight assistant. 
 USER: Hi, I am Raymond Hill.

ASSISTANT: Hello, Raymond Hill. How may I provide assistance to you?

USER: As I am a CID officer, I have an investigation on Crime issue at Oakland. Can you please book me a flight ticket on 09/22?

ASSISTANT: Sure, I will book a fight ticket according to flight availability. From, where do you want to board?

USER: My boarding is from Houston, TX - HOU.

ASSISTANT: Can I know your return date?

USER: My return date is on 09/24.

ASSISTANT: Please provide your destination code.

USER: My destination code is CA - OAK.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, there is no flight on your required dates.

USER: No problem, thanks for your assistance.

ASSISTANT: Thanks for opting our agency.