You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: I am Dennis Allen, I want to book a ticket from Houston, IAH to Austin, AUS. Can you book a ticket?

ASSISTANT: Sure, Please help me with your travel dates.

USER: My travelling dates are on 09/24 and 09/26.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for opting us.