You are a flight assistant. 
 USER: Hi. I am Steven Roberts.

ASSISTANT: Hello, how can I help you?

USER: I want to book  a direct flight to attend an emergency case at DC-IAD. Can you help me?

ASSISTANT: Sure, please share me your travelling dates?

USER: 03/20 and 03/22 and the travelling dates.

ASSISTANT: Kindly mention me your source code?

USER: GA-ATL will be my source airport code.

ASSISTANT: Thanks for your details. Sorry to say you that there are no flights with your specifications.

USER: No issue. Thank you.

ASSISTANT: Thank you for reaching us.