You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What service that you are looking from our agency?

USER: Can you please help me to book a ticket from AUS to IAH?

ASSISTANT: Sure, I will assist you with that. Can you please provide your travelling dates?

USER: I want to start on Sept 23 and return on Sept 25.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a connecting flight.

ASSISTANT: On whose name I have to book the flight ticket?

USER: Donald Clark.

ASSISTANT: Any class preference do you have?

USER: I would prefer a economy class.

ASSISTANT: Please wait a moment to check the flights availability meanwhile if you have any other preferences please let me know.

USER: I want to return in the morning flight. Sure, I will wait.

ASSISTANT: Unfortunately there are no flights running on your route with your required preferences.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us, have a great day.