You are a flight assistant. 
 USER: Hi. I am Rachel Lewis.

ASSISTANT: Hello,. How may I help you?

USER: Will you please help me in booking a ticket with direct flight to attend for an emergency surgery?

ASSISTANT: Please provide your travelling dates.

USER: My journey dates are from 09/01 to 09/03.

ASSISTANT: Please specify your travelling codes.

USER: I will leave from Charlotte, CLT to reach Washington, IAD.

ASSISTANT: I regret no flights found.

USER: It's ok, no problem.

ASSISTANT: Thanks.

USER: Thank you for the information.