You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Joshua Brown here.

ASSISTANT: How may I assist you?

USER: I want to travel from Houston to Oakland for attending a Seminar. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, can I have your nearest source and destination airport codes please?

USER: My airport codes are from HOU to OAK.

ASSISTANT: May I know your planned journey dates please?

USER: My travelling dates are from 09/07 to 09/09.

ASSISTANT: Please wait a moment.

USER: Ok, I will wait.

ASSISTANT: Brown, no flights has been found on your planned journey dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.