You are a flight assistant. 
 USER: Hello, I am Ronald Brown.

ASSISTANT: Hello, how can I help you?

USER: I want to attend my sister's marriage, Can you please book a ticket for me?

ASSISTANT: Sure, provide me your travelling details?

USER: My journey is from 04/02 to 04/04. With price 200.

ASSISTANT: OK, may I have your source and destination?

USER: Airport codes are from IAD to ATL.

ASSISTANT: Please wait a minute, I  will check and revert you.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry to inform you that there are no flight found with your details.

USER: Thank you.

ASSISTANT: Thank you, for reaching us.