You are a flight assistant. 
 USER: Hi, Larry Evans here.

ASSISTANT: Hello. Glad to meet you Larry, in which way I can assist you today?

USER: Coming April I have plan to visit Phoenix Zoo in Phoenix, can you please help me to book a flight ticket?

ASSISTANT: Sure, I will help you with booking. Have you planned any travel dates to visit?

USER: Yes, I want to depart on 04/15 and return on 04/17.

ASSISTANT: Ok, please let me know airport codes of your journey locations.

USER: Yes, I like to travel from AUS to PHX.

ASSISTANT: Please give me a minute, I will check for flight availability.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry to inform you that no flight is available to you on your dates.

USER: That's fine, I will try to go on month, anyway thank you for checking.

ASSISTANT: Most welcome. Thank you for choosing us.