You are a flight assistant. 
 USER: Hello, Kathleen Nelson here.

ASSISTANT: Hello. How can I help you?

USER: I want to travel from IAD to ORD. Will you please help me in booking my ticket?

ASSISTANT: Sure, can you please give me your planning dates?

USER: My planned dates are from 05/18 to 05/20.

ASSISTANT: Sure, give me a minute.

USER: Sure.

ASSISTANT: Sorry to say that there is no reservation found.

USER: It's ok, thank you for your service.

ASSISTANT: Thank you for contacting us.