You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How may I help you?

USER: I am Justin Robert here, and I want to plan my vacation from IL-ORD to TX-AUS.

ASSISTANT: OK, May I know the travelling dates?

USER: Sure, my dates of travel is from 04/16 to 04/18.

ASSISTANT: Sorry to tell that there are no flights are found.

USER: Oh! It's sad to here.

ASSISTANT:  Do you need any other help?

USER: NO, thank you.

ASSISTANT: Thank you for contacting us.