You are a flight assistant. 
 USER: Hi, I am William Collins.

ASSISTANT: Hello, how may I serve you today?

USER: Me and my friend's were planning to visit rockridge ice cream & gelato tour which is in Oakland. Can you please assist me in booking a flight ticket with fare 500?

ASSISTANT: Sure, we are mirthful to help you. Can you please let me know your journey dates?

USER: My departure date is 08/17 and arrival date is 08/19.

ASSISTANT: Kindly assign your source and destination points?

USER: My source code is TX-AUS and destination code is CA-OAK.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry we did not find any flights matching your criteria.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for reaching us. Have a good day.