You are a flight assistant. 
 USER: Hello, My name is Larry King from Houston.

ASSISTANT: Hello, how can I aid you?

USER: I am an engineer and would like to attend for training session about robotics which is going to be conducted in Oakland, CA - OAK. Could you please help me for booking with a fare of 500?

ASSISTANT: Sure, we would be glad to help you.

USER: Thank you.

ASSISTANT: May I know your preferable dates to travel?

USER: My preferred journey dates are on 07/19 to 07/21.

ASSISTANT: Ok, from which airport you would like to depart?

USER: I will depart from Houston, TX - IAH.

ASSISTANT: Ok, please wait a moment. I will check the availability and get back to you.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no flight available on your dates.

USER: Ok, no problem at all. Thanks for your information.

ASSISTANT: Thank you for reaching us.