You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any assistance from us?

USER: I want to book a ticket from ORD to AUS, can you help me?

ASSISTANT: Sure, may I know your trip dates?

USER: My travel dates are 04/26 and 04/28.

ASSISTANT: Sure, could I know your name please?

USER: Myself Dennis Martin.

ASSISTANT: Dennis, there is no plane on your requested travelling dates.

USER: No problem, thanks for checking.

ASSISTANT: My pleasure, thank you for opting us.