You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Laura Nelson here. Can you please help me in booking a flight ticket from IAD to IAH?

ASSISTANT: Sure Nelson, can I know the travel dates please?

USER: Sure, my trip dates are from 04/07 to 04/09.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights found on your dates.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for approaching us.