You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Mark Jackson here.

ASSISTANT: Mark Jackson. How may I assist you?

USER: Please help me out in booking the ticket from IAH to AUS.

ASSISTANT: Sure, please provide me with the travel dates.

USER: My trip dates will be 04/28 to 04/30.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform that there are no flights on your desired dates.

USER: Please proceed. That's ok, not a issue. Thank you for informing.

ASSISTANT: Thank you for approaching us.