You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I have a program to attend, so could you help me to book a  ticket from LASt o AUS.

ASSISTANT: Sure. Tell me your class preference please?

USER: My class preference would be economy with single connection flight.

ASSISTANT: May I know your name please?

USER: My name is Michael Turner.

ASSISTANT: Now share your travel dates please?

USER: My travel dates are May 22 and Mat 24.

ASSISTANT: Do you have any other preferences?

USER: My depart time should be in the evening.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Sorry there no flights available in the evening time.

USER: No issue, thank you very much.

ASSISTANT: Thank you.