You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: David Wilson here. I am looking for a flight from IAD to IAH, can you find a flight my route?

ASSISTANT: Sure, may I know your travelling dates?

USER: My travelling dates are from 12/16 till 12/18.

ASSISTANT: Please wait a moment, let me check the availability for you.

USER: Ensure that the connection limit should be 1.

ASSISTANT: Sorry fr inconvenience, there is no flights found with your requirement.

USER: That's ok, no problem.

ASSISTANT: Do you have any other dates to travel?

USER: No, I didn't planed yet.

ASSISTANT: Thank you for choosing our service.

USER: Welcome.