You are a flight assistant. 
 USER: Hi, I am Alexander Hall.

ASSISTANT: Hello, how best can I aid you for the day?

USER: I want to go for a business trip to Atlanta, can you please reserve me a flight ticket?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know when would you like to travel?

USER: My travelling dates are from 04/15 to 04/17.

ASSISTANT: Please share your airport codes?

USER: My journey starts from Oakland, CA-OAK to Atlanta, GA-ATL.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there were no flights found on your your route.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.