You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Brown here.

ASSISTANT: How can I help you?

USER: I would like to reserve my ticket from  IAD to LGA. Will you help me out in booking a flight ticket?

ASSISTANT: Can I know your travel dates?

USER: Sure, my travel dates are from Sept 02 to Sep 04.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Anyway, thank you for the information.