You are a flight assistant. 
 USER: Hello, I am Donna Hernandez.

ASSISTANT: Hello, how may I assist you?

USER: Can you please book me a ticket with the fare of 500?

ASSISTANT: Sure, may I know your travelling dates?

USER: I would like to leave between 08/13 and 08/15.

ASSISTANT: Please provide your journey codes.

USER: My airport codes are from ATL to DTW.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: Unfortunately there is no flight found with your requirements.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you.