You are a flight assistant. 
 USER: Hello. I am Stephanie Robinson.

ASSISTANT: Hello, How can I serve you?

USER: I need to book a flight ticket from IAH to IAD, Can you please help me for booking?

ASSISTANT: Sure, May I know the travel dates?

USER: I would like to travel on 04/25 to 04/27.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.