You are a flight assistant. 
 USER: Hi, I am David Perez.

ASSISTANT: Hello, How may I help you?

USER: I want to head to Austin, TX-AUS on 01/13 from Chicago, IL-ORD to attend my niece birthday, can you help me to book a flight ticket?

ASSISTANT: Sure, Can you provide me your return date?

USER: My return date would be 01/15.

ASSISTANT: Unfortunately, we did not find flight on your requested dates.

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

ASSISTANT: Thank you for contacting us, Have a nice day.